The `BaseTool` expects the run_async to return a json-serializable object. By model_dump the McpTool result explicitly can allow what ADK runtime sees is identical to what is persisted in the session event list.
Before the change, runtime sees CallToolResult instance and Session persists its serialized dict.
https://github.com/modelcontextprotocol/python-sdk/blob/main/src/mcp/types.py#L916-L922
PiperOrigin-RevId: 822465432
Add a header_provider param which is a callable[ReadonlyContext, Dict[str, Any]] for users to build headers in MCPToolset
fix: https://github.com/google/adk-python/issues/3156
PiperOrigin-RevId: 820412372
Wei Sun (Jack)andCopybara-Service
Kathy WuandCopybara-Service
Xiang (Sean) ZhouandCopybara-Service