Python: Changes tools parameter type hints from MutableMapping to Mapping for broader type compatibility.

[giles17]

Motivation and Context

The tools parameter accepts dict-based tool definitions that are only read, never mutated.
Resolves #3577.

Description

Contribution Checklist

• The code builds clean without any errors or warnings
• The PR follows the Contribution Guidelines
• All unit tests pass, and I have added new tests where possible
• Is this a breaking change? If yes, add "[BREAKING]" prefix to the title of the PR.

[markwallace-microsoft]

Python Test Coverage Report •

File	Stmts	Miss	Cover	Missing
packages/core/agent_framework
_agents.py	320	35	89%	474, 887, 924, 1024–1026, 1139, 1180, 1182, 1191–1196, 1202, 1204, 1214–1215, 1222, 1224–1225, 1233–1237, 1245–1246, 1248, 1253, 1255, 1289, 1329, 1349
TOTAL	21097	3344	84%

Python Unit Test Overview

Tests	Skipped	Failures	Errors	Time
4061	225 💤	0 ❌	0 🔥	1m 12s ⏱️

[Copilot]

Pull request overview

Updates the Python agent API’s tools type hints to use Mapping instead of MutableMapping, reflecting that tool definitions are read-only and improving compatibility with more mapping types.

Changes:

• Switched tools parameter annotations from MutableMapping[str, Any] to Mapping[str, Any] in RawAgent/Agent constructors and run() overloads.
• Updated internal casts and normalized tool list annotations to match the new mapping type.

Comments suppressed due to low confidence (1)

python/packages/core/agent_framework/_agents.py:1016

• After widening the accepted tool-definition type to Mapping[str, Any], _prepare_run_context still types final_tools as ... | dict[str, Any] .... If callers pass a non-dict mapping (e.g., ChainMap/MappingProxyType), this becomes a type mismatch even though runtime behavior is fine. Consider widening final_tools (and any downstream tool list types) to Mapping[str, Any] for consistency with the new contract.

        normalized_tools: list[FunctionTool | Callable[..., Any] | Mapping[str, Any] | Any] = (
            [] if tools_ is None else tools_ if isinstance(tools_, list) else [tools_]
        )
        agent_name = self._get_agent_name()

        # Resolve final tool list (runtime provided tools + local MCP server tools)
        final_tools: list[FunctionTool | Callable[..., Any] | dict[str, Any] | Any] = []
        for tool in normalized_tools:
            if isinstance(tool, MCPTool):

[Copilot]

The tools parameter is typed as a Sequence[...], but normalization only treats list as a collection (isinstance(tools_, list)); passing a tuple/other sequence will be wrapped as a single item and the contained tools will be ignored downstream. Either restrict the type hint to list[...] (to match behavior) or update normalization/casts to accept any non-string Sequence and iterate over it.

Suggested change

	| Sequence[FunctionTool | Callable[..., Any] | Mapping[str, Any] | Any]
	| list[FunctionTool | Callable[..., Any] | Mapping[str, Any] | Any]