Problem

Pydantic derives a title from every tool argument name in the published JSON Schema. For example, exercise_id becomes "title": "Exercise Id"; the title repeats the property key and increases the tool schema sent to models on every request.

Root Cause

Tool.from_function calls Pydantic's default model_json_schema, whose generator adds field-name titles whenever a field does not provide an explicit title.

Solution

Use a strict schema generator for tool input models that disables only Pydantic's automatic field-name title generation. Explicit Field(title=...) metadata remains unchanged.

Changes

• Add NoTitleJsonSchema, based on the existing strict generator, with field_title_should_be_set disabled.
• Use it when Tool.from_function builds the input schema.
• Add an integration regression test covering both derived and explicit field titles.

Testing

• py -3.10 -m pytest -q --noconftest tests/server/mcpserver/test_title.py tests/server/mcpserver/test_func_metadata.py (passed: 64)
• py -3.10 -m ruff check src/mcp/server/mcpserver/utilities/func_metadata.py src/mcp/server/mcpserver/tools/base.py tests/server/mcpserver/test_title.py (passed)
• py -3.10 -m ruff format --check src/mcp/server/mcpserver/utilities/func_metadata.py src/mcp/server/mcpserver/tools/base.py tests/server/mcpserver/test_title.py (passed)
• py -3.10 -m compileall -q src/mcp/server/mcpserver/utilities/func_metadata.py src/mcp/server/mcpserver/tools/base.py tests/server/mcpserver/test_title.py (passed)
• git diff --check (passed)
• Full typecheck was not verified locally because the partial Git checkout did not contain the configured mcp-types environment; the targeted runtime and static checks above passed.

Compatibility/Risk

This changes only generated tool input schemas. It removes redundant auto-derived property titles while preserving explicit titles and all other validation metadata. Consumers that depended on Pydantic's derived titles may observe a smaller schema, but property names and types are unchanged.

Notes for Reviewer

Please confirm that removing default property titles is the desired default for MCP tool schemas, and whether output schemas, prompts, or resource templates should follow in a separate change.

Linked Issue

Closes #3391