diff --git a/mise.toml b/mise.toml
index d5ccaba..89528a2 100644
--- a/mise.toml
+++ b/mise.toml
@@ -5,6 +5,8 @@
 jq = "1.8.1"
 node = "24.16.0"
 "npm:ajv-cli" = "5.0.0"
+"npm:json-schema-to-typescript" = "15.0.4"
+"npm:typescript" = "6.0.3"
 
 [tasks.setup]
 description = "Install tools and configure Git hooks"
@@ -24,7 +26,7 @@ run = "hk check"
 
 [tasks.test]
 description = "Run tests for this repository"
-depends = ["check:json", "check:schema", "check:conformance"]
+depends = ["check:json", "check:schema", "check:conformance", "check:typescript-generation"]
 
 [tasks."check:json"]
 description = "Validate JSON and JSONL syntax"
@@ -47,6 +49,10 @@ node scripts/check-schema-descriptions.mjs
 description = "Validate conformance manifest documentation and diagnostic registry"
 run = "node scripts/check-conformance.mjs"
 
+[tasks."check:typescript-generation"]
+description = "Validate release schema TypeScript generation and smoke contracts"
+run = "node scripts/check-typescript-generation.mjs"
+
 [tasks."check:actions"]
 description = "Validate GitHub Actions workflows"
 run = "if [ -d .github/workflows ]; then actionlint && zizmor .github/workflows; else echo 'No GitHub Actions workflows configured.'; fi"
diff --git a/schema/draft.json b/schema/draft.json
index 63db1af..048df90 100644
--- a/schema/draft.json
+++ b/schema/draft.json
@@ -1174,1385 +1174,307 @@
         "properties": {
           "type": { "const": "tool_call", "description": "Tool call event discriminator." },
           "payload": {
-            "oneOf": [
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "file_read",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallFileReadArgs",
-                    "description": "Arguments for a file read tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Non-truncated file read tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "file_read",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallFileReadArgs",
-                    "description": "Arguments for a file read tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Truncated file read tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "file_write",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallFileWriteArgs",
-                    "description": "Arguments for a file write tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Non-truncated file write tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "file_write",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallFileWriteArgs",
-                    "description": "Arguments for a file write tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Truncated file write tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "file_edit",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallFileEditArgs",
-                    "description": "Arguments for a file edit tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Non-truncated file edit tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "file_edit",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallFileEditArgs",
-                    "description": "Arguments for a file edit tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Truncated file edit tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "file_patch",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallFilePatchArgs",
-                    "description": "Arguments for an atomic multi-file patch tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Non-truncated file patch tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "file_patch",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallFilePatchArgs",
-                    "description": "Arguments for an atomic multi-file patch tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Truncated file patch tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "file_list",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallFileListArgs",
-                    "description": "Arguments for a file listing tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Non-truncated file list tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "file_list",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallFileListArgs",
-                    "description": "Arguments for a file listing tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Truncated file list tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "file_search",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallFileSearchArgs",
-                    "description": "Arguments for a file search tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Non-truncated file search tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "file_search",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallFileSearchArgs",
-                    "description": "Arguments for a file search tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Truncated file search tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "shell_command",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallShellCommandArgs",
-                    "description": "Arguments for a shell command tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Non-truncated shell command tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "shell_command",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallShellCommandArgs",
-                    "description": "Arguments for a shell command tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Truncated shell command tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "shell_output",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallShellOutputArgs",
-                    "description": "Arguments for polling shell command output."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Non-truncated shell output tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "shell_output",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallShellOutputArgs",
-                    "description": "Arguments for polling shell command output."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Truncated shell output tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "shell_input",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallShellInputArgs",
-                    "description": "Arguments for sending input to a running shell command."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Non-truncated shell input tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "shell_input",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallShellInputArgs",
-                    "description": "Arguments for sending input to a running shell command."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Truncated shell input tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "mcp_call",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallMcpCallArgs",
-                    "description": "Arguments for an MCP tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Non-truncated mcp call tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "mcp_call",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallMcpCallArgs",
-                    "description": "Arguments for an MCP tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Truncated mcp call tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "web_fetch",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallWebFetchArgs",
-                    "description": "Arguments for a web fetch tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Non-truncated web fetch tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "web_fetch",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallWebFetchArgs",
-                    "description": "Arguments for a web fetch tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Truncated web fetch tool call payload."
-              },
+            "allOf": [
               {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "web_search",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallWebSearchArgs",
-                    "description": "Arguments for a web search tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
+                "oneOf": [
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
                     ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Non-truncated web search tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "web_search",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallWebSearchArgs",
-                    "description": "Arguments for a web search tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
+                    "properties": {
+                      "tool": {
+                        "const": "file_read",
+                        "description": "Canonical kind of tool requested by the agent."
                       },
-                      {
-                        "type": "null"
+                      "args": {
+                        "$ref": "#/$defs/toolCallFileReadArgs",
+                        "description": "Arguments for a file read tool call."
                       }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Truncated web search tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "tool_search",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallToolSearchArgs",
-                    "description": "Arguments for a tool discovery search."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
+                    },
+                    "description": "Tool call payload for file read."
                   },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
+                    ],
+                    "properties": {
+                      "tool": {
+                        "const": "file_write",
+                        "description": "Canonical kind of tool requested by the agent."
                       },
-                      {
-                        "type": "null"
+                      "args": {
+                        "$ref": "#/$defs/toolCallFileWriteArgs",
+                        "description": "Arguments for a file write tool call."
                       }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Non-truncated tool search tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "tool_search",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallToolSearchArgs",
-                    "description": "Arguments for a tool discovery search."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
+                    },
+                    "description": "Tool call payload for file write."
                   },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
+                    ],
+                    "properties": {
+                      "tool": {
+                        "const": "file_edit",
+                        "description": "Canonical kind of tool requested by the agent."
                       },
-                      {
-                        "type": "null"
+                      "args": {
+                        "$ref": "#/$defs/toolCallFileEditArgs",
+                        "description": "Arguments for a file edit tool call."
                       }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Truncated tool search tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "notebook_edit",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallNotebookEditArgs",
-                    "description": "Arguments for a notebook edit tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
+                    },
+                    "description": "Tool call payload for file edit."
                   },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
+                    ],
+                    "properties": {
+                      "tool": {
+                        "const": "file_patch",
+                        "description": "Canonical kind of tool requested by the agent."
                       },
-                      {
-                        "type": "null"
+                      "args": {
+                        "$ref": "#/$defs/toolCallFilePatchArgs",
+                        "description": "Arguments for an atomic multi-file patch tool call."
                       }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Non-truncated notebook edit tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "notebook_edit",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallNotebookEditArgs",
-                    "description": "Arguments for a notebook edit tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
+                    },
+                    "description": "Tool call payload for file patch."
                   },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
+                    ],
+                    "properties": {
+                      "tool": {
+                        "const": "file_list",
+                        "description": "Canonical kind of tool requested by the agent."
                       },
-                      {
-                        "type": "null"
+                      "args": {
+                        "$ref": "#/$defs/toolCallFileListArgs",
+                        "description": "Arguments for a file listing tool call."
                       }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Truncated notebook edit tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "subagent_invoke",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallSubagentInvokeArgs",
-                    "description": "Arguments for invoking a subagent."
+                    },
+                    "description": "Tool call payload for file list."
                   },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
+                    ],
+                    "properties": {
+                      "tool": {
+                        "const": "file_search",
+                        "description": "Canonical kind of tool requested by the agent."
+                      },
+                      "args": {
+                        "$ref": "#/$defs/toolCallFileSearchArgs",
+                        "description": "Arguments for a file search tool call."
+                      }
+                    },
+                    "description": "Tool call payload for file search."
                   },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
+                    ],
+                    "properties": {
+                      "tool": {
+                        "const": "shell_command",
+                        "description": "Canonical kind of tool requested by the agent."
+                      },
+                      "args": {
+                        "$ref": "#/$defs/toolCallShellCommandArgs",
+                        "description": "Arguments for a shell command tool call."
+                      }
+                    },
+                    "description": "Tool call payload for shell command."
                   },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
+                    ],
+                    "properties": {
+                      "tool": {
+                        "const": "shell_output",
+                        "description": "Canonical kind of tool requested by the agent."
+                      },
+                      "args": {
+                        "$ref": "#/$defs/toolCallShellOutputArgs",
+                        "description": "Arguments for polling shell command output."
+                      }
+                    },
+                    "description": "Tool call payload for shell output."
                   },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
+                    ],
+                    "properties": {
+                      "tool": {
+                        "const": "shell_input",
+                        "description": "Canonical kind of tool requested by the agent."
                       },
-                      {
-                        "type": "null"
+                      "args": {
+                        "$ref": "#/$defs/toolCallShellInputArgs",
+                        "description": "Arguments for sending input to a running shell command."
                       }
+                    },
+                    "description": "Tool call payload for shell input."
+                  },
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
                     ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Non-truncated subagent invoke tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "subagent_invoke",
-                    "description": "Canonical kind of tool requested by the agent."
+                    "properties": {
+                      "tool": {
+                        "const": "mcp_call",
+                        "description": "Canonical kind of tool requested by the agent."
+                      },
+                      "args": {
+                        "$ref": "#/$defs/toolCallMcpCallArgs",
+                        "description": "Arguments for an MCP tool call."
+                      }
+                    },
+                    "description": "Tool call payload for mcp call."
                   },
-                  "args": {
-                    "$ref": "#/$defs/toolCallSubagentInvokeArgs",
-                    "description": "Arguments for invoking a subagent."
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
+                    ],
+                    "properties": {
+                      "tool": {
+                        "const": "web_fetch",
+                        "description": "Canonical kind of tool requested by the agent."
+                      },
+                      "args": {
+                        "$ref": "#/$defs/toolCallWebFetchArgs",
+                        "description": "Arguments for a web fetch tool call."
+                      }
+                    },
+                    "description": "Tool call payload for web fetch."
                   },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
+                    ],
+                    "properties": {
+                      "tool": {
+                        "const": "web_search",
+                        "description": "Canonical kind of tool requested by the agent."
+                      },
+                      "args": {
+                        "$ref": "#/$defs/toolCallWebSearchArgs",
+                        "description": "Arguments for a web search tool call."
+                      }
+                    },
+                    "description": "Tool call payload for web search."
                   },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
+                    ],
+                    "properties": {
+                      "tool": {
+                        "const": "tool_search",
+                        "description": "Canonical kind of tool requested by the agent."
+                      },
+                      "args": {
+                        "$ref": "#/$defs/toolCallToolSearchArgs",
+                        "description": "Arguments for a tool discovery search."
+                      }
+                    },
+                    "description": "Tool call payload for tool search."
                   },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
+                    ],
+                    "properties": {
+                      "tool": {
+                        "const": "notebook_edit",
+                        "description": "Canonical kind of tool requested by the agent."
+                      },
+                      "args": {
+                        "$ref": "#/$defs/toolCallNotebookEditArgs",
+                        "description": "Arguments for a notebook edit tool call."
+                      }
+                    },
+                    "description": "Tool call payload for notebook edit."
                   },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
+                    ],
+                    "properties": {
+                      "tool": {
+                        "const": "subagent_invoke",
+                        "description": "Canonical kind of tool requested by the agent."
                       },
-                      {
-                        "type": "null"
+                      "args": {
+                        "$ref": "#/$defs/toolCallSubagentInvokeArgs",
+                        "description": "Arguments for invoking a subagent."
                       }
+                    },
+                    "description": "Tool call payload for subagent invoke."
+                  },
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
                     ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
+                    "properties": {
+                      "tool": {
+                        "const": "other",
+                        "description": "Canonical kind of tool requested by the agent."
+                      },
+                      "args": {
+                        "$ref": "#/$defs/toolCallOtherArgs",
+                        "description": "Opaque arguments for the unclassified tool call."
+                      }
+                    },
+                    "description": "Tool call payload for other."
                   }
-                },
-                "additionalProperties": false,
-                "description": "Truncated subagent invoke tool call payload."
+                ],
+                "description": "Registered tool call discriminator and arguments."
               },
               {
                 "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
                 "properties": {
-                  "tool": {
-                    "const": "other",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallOtherArgs",
-                    "description": "Opaque arguments for the unclassified tool call."
-                  },
                   "usage": {
                     "$ref": "#/$defs/agentMessageUsage",
                     "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
                   },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
                   "overflow_ref": {
                     "oneOf": [
                       {
@@ -2566,56 +1488,49 @@
                     "description": "Content-addressed reference to full arguments when arguments are truncated."
                   }
                 },
-                "additionalProperties": false,
-                "description": "Non-truncated other tool call payload."
+                "description": "Optional fields shared by all tool call payloads."
               },
               {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "other",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallOtherArgs",
-                    "description": "Opaque arguments for the unclassified tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
+                "oneOf": [
+                  {
+                    "type": "object",
+                    "required": [
+                      "truncated",
+                      "args_size"
+                    ],
+                    "properties": {
+                      "truncated": {
+                        "const": true,
+                        "description": "Whether tool-call arguments were truncated before emission."
+                      },
+                      "args_size": {
+                        "type": "integer",
+                        "minimum": 0,
+                        "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
+                      }
+                    },
+                    "description": "Truncated tool call arguments marker."
                   },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
+                  {
+                    "type": "object",
+                    "properties": {
+                      "truncated": {
+                        "const": false,
+                        "description": "Whether tool-call arguments were truncated before emission."
                       },
-                      {
-                        "type": "null"
+                      "args_size": {
+                        "type": "integer",
+                        "minimum": 0,
+                        "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
                       }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
+                    },
+                    "description": "Non-truncated tool call arguments marker."
                   }
-                },
-                "additionalProperties": false,
-                "description": "Truncated other tool call payload."
+                ],
+                "description": "Tool call argument truncation state."
               }
             ],
+            "unevaluatedProperties": false,
             "description": "Tool call event payload."
           }
         }
diff --git a/schema/v0.1.0.json b/schema/v0.1.0.json
index 63db1af..048df90 100644
--- a/schema/v0.1.0.json
+++ b/schema/v0.1.0.json
@@ -1174,1385 +1174,307 @@
         "properties": {
           "type": { "const": "tool_call", "description": "Tool call event discriminator." },
           "payload": {
-            "oneOf": [
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "file_read",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallFileReadArgs",
-                    "description": "Arguments for a file read tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Non-truncated file read tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "file_read",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallFileReadArgs",
-                    "description": "Arguments for a file read tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Truncated file read tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "file_write",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallFileWriteArgs",
-                    "description": "Arguments for a file write tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Non-truncated file write tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "file_write",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallFileWriteArgs",
-                    "description": "Arguments for a file write tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Truncated file write tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "file_edit",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallFileEditArgs",
-                    "description": "Arguments for a file edit tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Non-truncated file edit tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "file_edit",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallFileEditArgs",
-                    "description": "Arguments for a file edit tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Truncated file edit tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "file_patch",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallFilePatchArgs",
-                    "description": "Arguments for an atomic multi-file patch tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Non-truncated file patch tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "file_patch",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallFilePatchArgs",
-                    "description": "Arguments for an atomic multi-file patch tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Truncated file patch tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "file_list",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallFileListArgs",
-                    "description": "Arguments for a file listing tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Non-truncated file list tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "file_list",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallFileListArgs",
-                    "description": "Arguments for a file listing tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Truncated file list tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "file_search",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallFileSearchArgs",
-                    "description": "Arguments for a file search tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Non-truncated file search tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "file_search",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallFileSearchArgs",
-                    "description": "Arguments for a file search tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Truncated file search tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "shell_command",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallShellCommandArgs",
-                    "description": "Arguments for a shell command tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Non-truncated shell command tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "shell_command",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallShellCommandArgs",
-                    "description": "Arguments for a shell command tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Truncated shell command tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "shell_output",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallShellOutputArgs",
-                    "description": "Arguments for polling shell command output."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Non-truncated shell output tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "shell_output",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallShellOutputArgs",
-                    "description": "Arguments for polling shell command output."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Truncated shell output tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "shell_input",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallShellInputArgs",
-                    "description": "Arguments for sending input to a running shell command."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Non-truncated shell input tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "shell_input",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallShellInputArgs",
-                    "description": "Arguments for sending input to a running shell command."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Truncated shell input tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "mcp_call",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallMcpCallArgs",
-                    "description": "Arguments for an MCP tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Non-truncated mcp call tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "mcp_call",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallMcpCallArgs",
-                    "description": "Arguments for an MCP tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Truncated mcp call tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "web_fetch",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallWebFetchArgs",
-                    "description": "Arguments for a web fetch tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Non-truncated web fetch tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "web_fetch",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallWebFetchArgs",
-                    "description": "Arguments for a web fetch tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Truncated web fetch tool call payload."
-              },
+            "allOf": [
               {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "web_search",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallWebSearchArgs",
-                    "description": "Arguments for a web search tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
-                      },
-                      {
-                        "type": "null"
-                      }
+                "oneOf": [
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
                     ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Non-truncated web search tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "web_search",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallWebSearchArgs",
-                    "description": "Arguments for a web search tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
+                    "properties": {
+                      "tool": {
+                        "const": "file_read",
+                        "description": "Canonical kind of tool requested by the agent."
                       },
-                      {
-                        "type": "null"
+                      "args": {
+                        "$ref": "#/$defs/toolCallFileReadArgs",
+                        "description": "Arguments for a file read tool call."
                       }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Truncated web search tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "tool_search",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallToolSearchArgs",
-                    "description": "Arguments for a tool discovery search."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
+                    },
+                    "description": "Tool call payload for file read."
                   },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
+                    ],
+                    "properties": {
+                      "tool": {
+                        "const": "file_write",
+                        "description": "Canonical kind of tool requested by the agent."
                       },
-                      {
-                        "type": "null"
+                      "args": {
+                        "$ref": "#/$defs/toolCallFileWriteArgs",
+                        "description": "Arguments for a file write tool call."
                       }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Non-truncated tool search tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "tool_search",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallToolSearchArgs",
-                    "description": "Arguments for a tool discovery search."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
+                    },
+                    "description": "Tool call payload for file write."
                   },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
+                    ],
+                    "properties": {
+                      "tool": {
+                        "const": "file_edit",
+                        "description": "Canonical kind of tool requested by the agent."
                       },
-                      {
-                        "type": "null"
+                      "args": {
+                        "$ref": "#/$defs/toolCallFileEditArgs",
+                        "description": "Arguments for a file edit tool call."
                       }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Truncated tool search tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "notebook_edit",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallNotebookEditArgs",
-                    "description": "Arguments for a notebook edit tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
+                    },
+                    "description": "Tool call payload for file edit."
                   },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
+                    ],
+                    "properties": {
+                      "tool": {
+                        "const": "file_patch",
+                        "description": "Canonical kind of tool requested by the agent."
                       },
-                      {
-                        "type": "null"
+                      "args": {
+                        "$ref": "#/$defs/toolCallFilePatchArgs",
+                        "description": "Arguments for an atomic multi-file patch tool call."
                       }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Non-truncated notebook edit tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "notebook_edit",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallNotebookEditArgs",
-                    "description": "Arguments for a notebook edit tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
+                    },
+                    "description": "Tool call payload for file patch."
                   },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
+                    ],
+                    "properties": {
+                      "tool": {
+                        "const": "file_list",
+                        "description": "Canonical kind of tool requested by the agent."
                       },
-                      {
-                        "type": "null"
+                      "args": {
+                        "$ref": "#/$defs/toolCallFileListArgs",
+                        "description": "Arguments for a file listing tool call."
                       }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Truncated notebook edit tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "subagent_invoke",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallSubagentInvokeArgs",
-                    "description": "Arguments for invoking a subagent."
+                    },
+                    "description": "Tool call payload for file list."
                   },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
+                    ],
+                    "properties": {
+                      "tool": {
+                        "const": "file_search",
+                        "description": "Canonical kind of tool requested by the agent."
+                      },
+                      "args": {
+                        "$ref": "#/$defs/toolCallFileSearchArgs",
+                        "description": "Arguments for a file search tool call."
+                      }
+                    },
+                    "description": "Tool call payload for file search."
                   },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
+                    ],
+                    "properties": {
+                      "tool": {
+                        "const": "shell_command",
+                        "description": "Canonical kind of tool requested by the agent."
+                      },
+                      "args": {
+                        "$ref": "#/$defs/toolCallShellCommandArgs",
+                        "description": "Arguments for a shell command tool call."
+                      }
+                    },
+                    "description": "Tool call payload for shell command."
                   },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
+                    ],
+                    "properties": {
+                      "tool": {
+                        "const": "shell_output",
+                        "description": "Canonical kind of tool requested by the agent."
+                      },
+                      "args": {
+                        "$ref": "#/$defs/toolCallShellOutputArgs",
+                        "description": "Arguments for polling shell command output."
+                      }
+                    },
+                    "description": "Tool call payload for shell output."
                   },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
+                    ],
+                    "properties": {
+                      "tool": {
+                        "const": "shell_input",
+                        "description": "Canonical kind of tool requested by the agent."
                       },
-                      {
-                        "type": "null"
+                      "args": {
+                        "$ref": "#/$defs/toolCallShellInputArgs",
+                        "description": "Arguments for sending input to a running shell command."
                       }
+                    },
+                    "description": "Tool call payload for shell input."
+                  },
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
                     ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
-                  }
-                },
-                "additionalProperties": false,
-                "description": "Non-truncated subagent invoke tool call payload."
-              },
-              {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "subagent_invoke",
-                    "description": "Canonical kind of tool requested by the agent."
+                    "properties": {
+                      "tool": {
+                        "const": "mcp_call",
+                        "description": "Canonical kind of tool requested by the agent."
+                      },
+                      "args": {
+                        "$ref": "#/$defs/toolCallMcpCallArgs",
+                        "description": "Arguments for an MCP tool call."
+                      }
+                    },
+                    "description": "Tool call payload for mcp call."
                   },
-                  "args": {
-                    "$ref": "#/$defs/toolCallSubagentInvokeArgs",
-                    "description": "Arguments for invoking a subagent."
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
+                    ],
+                    "properties": {
+                      "tool": {
+                        "const": "web_fetch",
+                        "description": "Canonical kind of tool requested by the agent."
+                      },
+                      "args": {
+                        "$ref": "#/$defs/toolCallWebFetchArgs",
+                        "description": "Arguments for a web fetch tool call."
+                      }
+                    },
+                    "description": "Tool call payload for web fetch."
                   },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
+                    ],
+                    "properties": {
+                      "tool": {
+                        "const": "web_search",
+                        "description": "Canonical kind of tool requested by the agent."
+                      },
+                      "args": {
+                        "$ref": "#/$defs/toolCallWebSearchArgs",
+                        "description": "Arguments for a web search tool call."
+                      }
+                    },
+                    "description": "Tool call payload for web search."
                   },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
+                    ],
+                    "properties": {
+                      "tool": {
+                        "const": "tool_search",
+                        "description": "Canonical kind of tool requested by the agent."
+                      },
+                      "args": {
+                        "$ref": "#/$defs/toolCallToolSearchArgs",
+                        "description": "Arguments for a tool discovery search."
+                      }
+                    },
+                    "description": "Tool call payload for tool search."
                   },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
+                    ],
+                    "properties": {
+                      "tool": {
+                        "const": "notebook_edit",
+                        "description": "Canonical kind of tool requested by the agent."
+                      },
+                      "args": {
+                        "$ref": "#/$defs/toolCallNotebookEditArgs",
+                        "description": "Arguments for a notebook edit tool call."
+                      }
+                    },
+                    "description": "Tool call payload for notebook edit."
                   },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
+                    ],
+                    "properties": {
+                      "tool": {
+                        "const": "subagent_invoke",
+                        "description": "Canonical kind of tool requested by the agent."
                       },
-                      {
-                        "type": "null"
+                      "args": {
+                        "$ref": "#/$defs/toolCallSubagentInvokeArgs",
+                        "description": "Arguments for invoking a subagent."
                       }
+                    },
+                    "description": "Tool call payload for subagent invoke."
+                  },
+                  {
+                    "type": "object",
+                    "required": [
+                      "tool",
+                      "args"
                     ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
+                    "properties": {
+                      "tool": {
+                        "const": "other",
+                        "description": "Canonical kind of tool requested by the agent."
+                      },
+                      "args": {
+                        "$ref": "#/$defs/toolCallOtherArgs",
+                        "description": "Opaque arguments for the unclassified tool call."
+                      }
+                    },
+                    "description": "Tool call payload for other."
                   }
-                },
-                "additionalProperties": false,
-                "description": "Truncated subagent invoke tool call payload."
+                ],
+                "description": "Registered tool call discriminator and arguments."
               },
               {
                 "type": "object",
-                "required": [
-                  "tool",
-                  "args"
-                ],
                 "properties": {
-                  "tool": {
-                    "const": "other",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallOtherArgs",
-                    "description": "Opaque arguments for the unclassified tool call."
-                  },
                   "usage": {
                     "$ref": "#/$defs/agentMessageUsage",
                     "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
                   },
-                  "truncated": {
-                    "const": false,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
-                  },
                   "overflow_ref": {
                     "oneOf": [
                       {
@@ -2566,56 +1488,49 @@
                     "description": "Content-addressed reference to full arguments when arguments are truncated."
                   }
                 },
-                "additionalProperties": false,
-                "description": "Non-truncated other tool call payload."
+                "description": "Optional fields shared by all tool call payloads."
               },
               {
-                "type": "object",
-                "required": [
-                  "tool",
-                  "args",
-                  "truncated",
-                  "args_size"
-                ],
-                "properties": {
-                  "tool": {
-                    "const": "other",
-                    "description": "Canonical kind of tool requested by the agent."
-                  },
-                  "args": {
-                    "$ref": "#/$defs/toolCallOtherArgs",
-                    "description": "Opaque arguments for the unclassified tool call."
-                  },
-                  "usage": {
-                    "$ref": "#/$defs/agentMessageUsage",
-                    "description": "Token usage attached to this tool call when it is the first usage-capable derived entry."
-                  },
-                  "truncated": {
-                    "const": true,
-                    "description": "Whether tool-call arguments were truncated before emission."
-                  },
-                  "args_size": {
-                    "type": "integer",
-                    "minimum": 0,
-                    "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
+                "oneOf": [
+                  {
+                    "type": "object",
+                    "required": [
+                      "truncated",
+                      "args_size"
+                    ],
+                    "properties": {
+                      "truncated": {
+                        "const": true,
+                        "description": "Whether tool-call arguments were truncated before emission."
+                      },
+                      "args_size": {
+                        "type": "integer",
+                        "minimum": 0,
+                        "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
+                      }
+                    },
+                    "description": "Truncated tool call arguments marker."
                   },
-                  "overflow_ref": {
-                    "oneOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^sha256:[a-f0-9]{64}$"
+                  {
+                    "type": "object",
+                    "properties": {
+                      "truncated": {
+                        "const": false,
+                        "description": "Whether tool-call arguments were truncated before emission."
                       },
-                      {
-                        "type": "null"
+                      "args_size": {
+                        "type": "integer",
+                        "minimum": 0,
+                        "description": "UTF-8 byte length of the original args object before truncation. Required when truncated is true."
                       }
-                    ],
-                    "description": "Content-addressed reference to full arguments when arguments are truncated."
+                    },
+                    "description": "Non-truncated tool call arguments marker."
                   }
-                },
-                "additionalProperties": false,
-                "description": "Truncated other tool call payload."
+                ],
+                "description": "Tool call argument truncation state."
               }
             ],
+            "unevaluatedProperties": false,
             "description": "Tool call event payload."
           }
         }
diff --git a/scripts/check-typescript-generation.mjs b/scripts/check-typescript-generation.mjs
new file mode 100644
index 0000000..07f2081
--- /dev/null
+++ b/scripts/check-typescript-generation.mjs
@@ -0,0 +1,219 @@
+import { execFile } from "node:child_process";
+import { mkdtemp, readFile, realpath, writeFile } from "node:fs/promises";
+import { createRequire } from "node:module";
+import { dirname, join } from "node:path";
+import { fileURLToPath } from "node:url";
+import { tmpdir } from "node:os";
+
+const repoRoot = new URL("../", import.meta.url);
+const schemaUrl = new URL("schema/v0.1.0.json", repoRoot);
+const scriptPath = fileURLToPath(import.meta.url);
+const generationTimeoutMs = Number(process.env.AGENT_TRAIL_TS_GENERATION_TIMEOUT_MS ?? 10_000);
+const commandTimeoutMs = 10_000;
+
+function fail(message) {
+  console.error(message);
+  process.exit(1);
+}
+
+function execFilePromise(command, args, options = {}) {
+  return new Promise((resolve, reject) => {
+    execFile(command, args, options, (error, stdout, stderr) => {
+      if (error !== null) {
+        error.stdout = stdout;
+        error.stderr = stderr;
+        reject(error);
+        return;
+      }
+      resolve({ stdout, stderr });
+    });
+  });
+}
+
+async function run(command, args, options = {}) {
+  try {
+    return await execFilePromise(command, args, {
+      cwd: fileURLToPath(repoRoot),
+      encoding: "utf8",
+      maxBuffer: 20 * 1024 * 1024,
+      timeout: commandTimeoutMs,
+      ...options,
+    });
+  } catch (error) {
+    const details = [error.message, error.stdout, error.stderr].filter(Boolean).join("\n");
+    throw new Error(`${command} ${args.join(" ")} failed:\n${details}`);
+  }
+}
+
+async function findPackageRoot(binName, packageName) {
+  const { stdout } = await run("mise", ["which", binName]);
+  let current = dirname(await realpath(stdout.trim()));
+
+  while (current !== dirname(current)) {
+    try {
+      const packageJson = JSON.parse(await readFile(join(current, "package.json"), "utf8"));
+      if (packageJson.name === packageName) return current;
+    } catch {
+      // Keep walking to the package root.
+    }
+    current = dirname(current);
+  }
+
+  throw new Error(`Unable to resolve ${packageName} from ${binName}.`);
+}
+
+async function loadJsonSchemaToTypescript() {
+  const require = createRequire(import.meta.url);
+  try {
+    return require("json-schema-to-typescript");
+  } catch {
+    const packageRoot = await findPackageRoot("json2ts", "json-schema-to-typescript");
+    return require(packageRoot);
+  }
+}
+
+async function runGenerateChild() {
+  const { compile } = await loadJsonSchemaToTypescript();
+  const schema = JSON.parse(await readFile(schemaUrl, "utf8"));
+  const generated = await compile(schema, "AgentTrail", {
+    bannerComment: "",
+    cwd: fileURLToPath(repoRoot),
+    format: false,
+    strictIndexSignatures: true,
+    unreachableDefinitions: true,
+    unknownAny: true,
+  });
+
+  process.stdout.write(generated);
+}
+
+async function generateTypes() {
+  const start = performance.now();
+  try {
+    const { stdout } = await execFilePromise(process.execPath, [scriptPath], {
+      cwd: fileURLToPath(repoRoot),
+      encoding: "utf8",
+      env: { ...process.env, AGENT_TRAIL_TS_GENERATE_CHILD: "1" },
+      maxBuffer: 20 * 1024 * 1024,
+      timeout: generationTimeoutMs,
+    });
+    const elapsedMs = performance.now() - start;
+    return { source: stdout, elapsedMs };
+  } catch (error) {
+    if (error.killed || error.signal === "SIGTERM") {
+      throw new Error(
+        `json-schema-to-typescript exceeded ${generationTimeoutMs}ms for schema/v0.1.0.json.`,
+      );
+    }
+    const details = [error.message, error.stdout, error.stderr].filter(Boolean).join("\n");
+    throw new Error(`json-schema-to-typescript failed:\n${details}`);
+  }
+}
+
+function smokeSource() {
+  return `import type { AgentTrailV010 } from "./agent-trail.generated";
+
+const id = "00000000-0000-4000-8000-000000000001";
+const ts = "2026-05-17T14:00:00.000Z";
+
+const validShellTruncated: AgentTrailV010 = { type: "tool_call", id, ts, payload: { tool: "shell_command", args: { command: "printf ok" }, truncated: true, args_size: 9 } };
+// @ts-expect-error truncated shell_command calls require args_size.
+const invalidShellMissingArgsSize: AgentTrailV010 = { type: "tool_call", id, ts, payload: { tool: "shell_command", args: { command: "printf ok" }, truncated: true } };
+// @ts-expect-error file_read args require path.
+const invalidFileReadMissingPath: AgentTrailV010 = { type: "tool_call", id, ts, payload: { tool: "file_read", args: {} } };
+const capabilityChangeJsonValues: AgentTrailV010 = { type: "capability_change", id, ts, payload: { scope: "tool", reason: "registered", changed: [{ name: "ToolSearch", field: "config", from: false, to: [1, "two", null] }] } };
+const vendorMetadataPrimitive: AgentTrailV010 = { type: "session_metadata_update", id, ts, payload: { field: "x-codex/value", value: 1, reason: "external" } };
+const vendorMetadataArray: AgentTrailV010 = { type: "session_metadata_update", id, ts, payload: { field: "x-codex/value", value: [1, "two", null], reason: "external" } };
+const vendorMetadataObject: AgentTrailV010 = { type: "session_metadata_update", id, ts, payload: { field: "x-codex/value", value: { nested: true, items: [1, null] }, reason: "external" } };
+const vendorMetadataNull: AgentTrailV010 = { type: "session_metadata_update", id, ts, payload: { field: "x-codex/value", value: null, reason: "external" } };
+
+void validShellTruncated;
+void invalidShellMissingArgsSize;
+void invalidFileReadMissingPath;
+void capabilityChangeJsonValues;
+void vendorMetadataPrimitive;
+void vendorMetadataArray;
+void vendorMetadataObject;
+void vendorMetadataNull;
+`;
+}
+
+async function assertSchemaRejectsUnknownToolPayloadField(tempDir) {
+  const samplePath = join(tempDir, "tool-call-extra-field.json");
+  await writeFile(
+    samplePath,
+    `${JSON.stringify({
+      type: "tool_call",
+      id: "00000000-0000-4000-8000-000000000002",
+      ts: "2026-05-17T14:00:00.000Z",
+      payload: {
+        tool: "shell_command",
+        args: { command: "printf ok" },
+        future_field: true,
+      },
+    })}\n`,
+  );
+
+  try {
+    await execFilePromise(
+      "ajv",
+      [
+        "validate",
+        "--spec=draft2020",
+        "--strict=false",
+        "--validate-formats=false",
+        "-s",
+        fileURLToPath(schemaUrl),
+        "-d",
+        samplePath,
+      ],
+      {
+        cwd: fileURLToPath(repoRoot),
+        encoding: "utf8",
+        maxBuffer: 1024 * 1024,
+        timeout: commandTimeoutMs,
+      },
+    );
+  } catch (error) {
+    if (error.code === 1) return;
+    throw error;
+  }
+
+  throw new Error("schema/v0.1.0.json allowed an unknown tool_call.payload field.");
+}
+
+async function runMain() {
+  const tempDir = await mkdtemp(join(tmpdir(), "agent-trail-tsgen-"));
+  const generatedPath = join(tempDir, "agent-trail.generated.d.ts");
+  const smokePath = join(tempDir, "agent-trail-smoke.ts");
+
+  const { source, elapsedMs } = await generateTypes();
+  await writeFile(generatedPath, source);
+  await writeFile(smokePath, smokeSource());
+
+  await run("tsc", [
+    "--noEmit",
+    "--strict",
+    "--skipLibCheck",
+    "--pretty",
+    "false",
+    "--target",
+    "ES2022",
+    "--module",
+    "NodeNext",
+    "--moduleResolution",
+    "NodeNext",
+    smokePath,
+  ]);
+
+  await assertSchemaRejectsUnknownToolPayloadField(tempDir);
+
+  console.log(`json-schema-to-typescript completed in ${Math.round(elapsedMs)}ms`);
+  console.log("TypeScript generation smoke checks passed");
+}
+
+if (process.env.AGENT_TRAIL_TS_GENERATE_CHILD === "1") {
+  await runGenerateChild();
+} else {
+  await runMain().catch((error) => fail(error.message));
+}