Sub-agents cannot call MCP tools due to agent-type tool restrictions

[nhorton]

Problem

When a sub-agent (spawned via the Agent tool) needs to call MCP tools (e.g., mcp__deepwork-dev__get_session_job), the call is denied by Claude Code's permission system — even when the user has added mcp__deepwork-dev__* to their ~/.claude/settings.json allow list.

Context

This was observed during a DeepPlan workflow where a quality review needed to call get_session_job to retrieve and review a registered session job definition. The review agent was spawned as subagent_type: general-purpose and:

1. Successfully called ToolSearch to load the MCP tool schema
2. Was denied permission when actually invoking the MCP tool

Root Cause Hypothesis

Agent types declare their available tools (e.g., general-purpose says Tools: *, Explore says Tools: All tools except Agent, ExitPlanMode, Edit, Write, NotebookEdit). MCP tools may not be included in the * wildcard, or the agent-type tool declarations may be a separate restriction layer from user-level permission settings.

Impact

• Quality reviews that need to inspect workflow state (e.g., reviewing a registered session job) cannot be delegated to sub-agents
• The parent agent must do the work itself or mark the review as passed without running it
• This limits the usefulness of DeepWork's review system for workflow-related outputs

Workaround

Read the session job file directly from disk (.deepwork/tmp/sessions/claude/session-{id}/jobs/{name}/job.yml) instead of calling the MCP tool.

🤖 Generated with Claude Code