fix(mcpserver): resolve TypedDict hints via typing_extensions for Python 3.10

`typing.get_type_hints` only strips the `Required`/`NotRequired` qualifier from
3.11 onwards. Below that the bare qualifier reached `create_model`, so on 3.10 --
a supported version -- ANY tool returning a TypedDict with `NotRequired` keys
failed at registration with PydanticForbiddenQualifier, before it could ever be
called. `typing_extensions.get_type_hints` strips it on every supported version.

Verified against unmodified upstream in a separate worktree: this crash predates
this branch and is not introduced by the structuredContent change.

Also switches the test module to `typing_extensions.TypedDict`, which pydantic
requires below 3.12 for `NotRequired` to be honoured.

Author: Sainikhil Juluri

src/mcp/server/mcpserver/utilities/func_metadata.py

@@ -4,7 +4,7 @@
 from collections.abc import Awaitable, Callable, Sequence
 from itertools import chain
 from types import GenericAlias
-from typing import Annotated, Any, Union, cast, get_args, get_origin, get_type_hints
+from typing import Annotated, Any, Union, cast, get_args, get_origin
 
 import anyio
 import anyio.to_thread
@@ -13,7 +13,7 @@
 from pydantic import BaseModel, ConfigDict, Field, PydanticUserError, WithJsonSchema, create_model
 from pydantic.fields import FieldInfo
 from pydantic.json_schema import GenerateJsonSchema, JsonSchemaWarningKind
-from typing_extensions import is_typeddict
+from typing_extensions import get_type_hints, is_typeddict
 from typing_inspection.introspection import (
     UNKNOWN,
     AnnotationSource,
@@ -514,6 +514,9 @@ def _create_model_from_typeddict(td_type: type[Any]) -> type[BaseModel]:
 
     The created model will have the same name and fields as the TypedDict.
     """
+    # `typing_extensions.get_type_hints` strips the `Required`/`NotRequired` qualifier on
+    # every supported version; `typing.get_type_hints` only does so from 3.11, and below
+    # that the bare qualifier reaches `create_model`, which pydantic rejects outright.
     type_hints = get_type_hints(td_type)
     required_keys = getattr(td_type, "__required_keys__", set(type_hints.keys()))
 

tests/server/mcpserver/test_func_metadata.py

@@ -5,15 +5,18 @@
 # pyright: reportUnknownLambdaType=false
 from collections.abc import Callable
 from dataclasses import dataclass
-from typing import Annotated, Any, Final, NamedTuple, TypedDict
+from typing import Annotated, Any, Final, NamedTuple
 
 import annotated_types
 import jsonschema
 import pytest
 from dirty_equals import IsPartialDict
 from mcp_types import CallToolResult, InputRequiredResult
 from pydantic import BaseModel, Field
-from typing_extensions import NotRequired
+
+# Pydantic requires `typing_extensions.TypedDict` (not `typing.TypedDict`) below 3.12,
+# otherwise a `NotRequired` qualifier is rejected as invalid in the context it is defined.
+from typing_extensions import NotRequired, TypedDict
 
 from mcp.server.mcpserver.exceptions import InvalidSignature
 from mcp.server.mcpserver.utilities.func_metadata import func_metadata