Python: Fix azurefunctions MCP tool invocation to use correct agent

[gavin-aguiar]

Motivation and Context

Summary

Fixed an issue for MCP tool invocations to route to the correct agent based on the thread id.

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/azurefunctions/agent_framework_azurefunctions
_app.py	374	83	77%	197–198, 203–204, 422, 430–431, 451–453, 459–461, 467–469, 502–503, 563–564, 613–614, 619, 699, 702, 711–713, 715–717, 719, 721, 732, 734–737, 739, 741–742, 744, 751–752, 754–755, 757–758, 760, 764, 774–776, 778–779, 781–783, 790, 792–793, 795, 816, 821, 833, 909, 921, 928–930, 975, 989, 1000–1002, 1004–1007, 1032, 1039, 1041, 1044
_models.py	155	12	92%	212, 215, 218, 230, 233, 252, 255, 260, 265, 282, 341, 360
TOTAL	17482	2704	84%

Python Unit Test Overview

Tests	Skipped	Failures	Errors	Time
3229	213 💤	0 ❌	0 🔥	1m 4s ⏱️

[Copilot]

Pull request overview

This pull request fixes an issue in the MCP tool invocation flow where the agent entity routing was incorrectly using the agent name embedded in the threadId parameter instead of the agent_name parameter passed to the handler function. The fix ensures that MCP tool invocations always route to the correct agent entity based on the invoked agent, not the agent name potentially stored in the thread ID from a previous conversation.

Changes:

• Modified thread ID parsing logic to extract only the session key from thread_id while always using the agent_name parameter for entity routing
• Added comprehensive test coverage for the scenario where thread_id contains a different agent name than the invoked agent

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
python/packages/azurefunctions/agent_framework_azurefunctions/_app.py	Updated _handle_mcp_tool_invocation to parse thread_id differently - extracting only the key portion while using the agent_name parameter for the entity name
python/packages/azurefunctions/tests/test_app.py	Added test case test_handle_mcp_tool_invocation_ignores_agent_name_in_thread_id to verify the fix works correctly when thread_id contains a different agent name