Add type annotations for all server decorators (list_tools, list_resources, read_resource)

[DaisukeYoda]

Summary

Following #1822 and #1826 which addressed call_tool decorator typing, the other server decorators still lack proper type annotations, requiring # type: ignore comments in strict mypy projects.

Affected Decorators

• @server.list_tools()
• @server.list_resources()
• @server.read_resource()

Current Behavior

@server.list_tools()  # type: ignore[no-untyped-call, untyped-decorator]
async def list_tools() -> list[Tool]:
    ...

@server.list_resources()  # type: ignore[no-untyped-call, untyped-decorator]
async def list_resources() -> list[Resource]:
    ...

@server.read_resource()  # type: ignore[no-untyped-call, untyped-decorator]
async def read_resource(uri: str) -> str:
    ...

Running mypy in strict mode produces:

error: Call to untyped function "list_tools" in typed context  [no-untyped-call]
error: Untyped decorator makes function "list_tools" untyped  [untyped-decorator]

Expected Behavior

All server decorators should preserve type information using ParamSpec (as done for call_tool in #1826), eliminating the need for type: ignore comments.

Environment

• mcp version: 1.26.0
• Python: 3.14
• mypy: strict mode

Related

• Decorator type signatures lose parameter types (use ParamSpec) #1822 - Original issue for call_tool
• fix: add explicit type annotation for call_tool decorator #1826 - Fix for call_tool decorator

[maxisbey]

Thanks! The low-level server API is being redesigned — see #1985. This will be addressed as part of that refactor.

_{AI Disclaimer}