feat!: #697 added tool input arguments validation

[ashakirin]

Added tool input arguments validation causes Tool Execution Error accordingly SEP-1303.
It is breaking change, because tool input validation is activated by default

[Kehrlann]

Now that I'm revisiting this, I'm wondering whether we really want this system property to toggle this on or off.

We're going to ship this in 2.0, let it be a breaking change - after all, servers MUST validate tool inputs.

(And we should probably revisit tool name validation too, then)

[ashakirin]

@Kehrlann regarding toggling:

• I think toggling makes sense for tool names, because validation is specified as SHOULD/SHOULD NOT in the spec;
• For server tool input schema validation, I'm not sure about toggling. The spec says MUST, so without validation the implementation would be non-spec-compliant. On the other hand, toggling could make SDK 2.0 adoption easier for some use cases. I agree to remove it.

[Kehrlann]

For toggling, I'm in favor of leaving an option to turn it off. But let's get rid of the system property - we don't use that pattern anywhere else in the codebase.
If users don't want validation, they should indicate that in the client.

[ashakirin]

@Kehrlann: Got it now — you meant we should reconsider using system properties specifically for tool name and input schema validation, not as a full toggle. That definitely makes sense for the input schema validation: I will remove the system property, but keep the toggle in the server builder. For tool names, server builder settings should be enough as well; exposing it as a system property is more the responsibility of a framework as the SDK. WDYT?

[Kehrlann]

For tool names, server builder settings should be enough as well; exposing it as a system property is more the responsibility of a framework as the SDK

Exactly.

For the tool names, you can do it in a separate PR.

[ashakirin]

@Kehrlann: I reworked PR with Map<String, Object> input schema

[Kehrlann]

Thanks for your contribution. For info I've simplified the integration test a bit.