Python: Updating MCP endpoint parameters to use snake case

[gavin-aguiar]

Motivation and Context

Fixes: #3031

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	368	85	76%	202–203, 208–209, 320–321, 429, 437–438, 458–460, 466–468, 474–476, 509–510, 570–571, 620–621, 626, 708, 711, 720–722, 724–726, 728, 730, 741, 743–746, 748, 750–751, 753, 760–761, 763–764, 766–767, 769, 773, 783–785, 787–788, 790–792, 799, 801–802, 804, 825, 830, 842, 917, 927, 934–936, 981, 995, 1006–1008, 1010–1013, 1038, 1045, 1047, 1050
TOTAL	16249	2024	87%

Python Unit Test Overview

Tests	Skipped	Failures	Errors	Time
3720	221 💤	0 ❌	0 🔥	1m 7s ⏱️

[Copilot]

Pull request overview

Updates the Azure Functions MCP tool trigger to use snake_case for the thread identifier parameter, aligning MCP parameter naming with other endpoints and addressing #3031.

Changes:

• Renamed MCP tool parameter from threadId to thread_id in the MCP tool properties schema.
• Updated MCP invocation handling to read thread_id from the MCP context arguments.
• Updated unit tests to send thread_id in MCP invocation contexts.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
python/packages/azurefunctions/agent_framework_azurefunctions/_app.py	Changes MCP tool schema + argument parsing to use thread_id instead of threadId.
python/packages/azurefunctions/tests/test_app.py	Updates MCP tool invocation tests to pass thread_id.

[Copilot]

Switching the MCP argument name from threadId to thread_id means existing MCP clients still sending threadId will silently lose conversation continuity (a breaking API behavior change). Consider accepting both keys during a transition period (e.g., read thread_id and fall back to threadId, optionally with a deprecation warning), or explicitly mark/document this as a breaking change for consumers.

Suggested change

	# Extract optional thread_id
	thread_id = arguments.get("thread_id")
	# Extract optional thread_id (prefer snake_case, but support legacy camelCase 'threadId')
	thread_id = arguments.get("thread_id")
	if thread_id is None:
	legacy_thread_id = arguments.get("threadId")
	if legacy_thread_id is not None:
	logger.warning(
	"MCP argument 'threadId' is deprecated; please use 'thread_id' instead."
	)
	thread_id = legacy_thread_id