Python: Improve AG-UI tool call argument protocol conformance

[White-Mouse]

Motivation & Context

AG-UI TOOL_CALL_ARGS events carry a tool-call identifier. The converter previously attached every argument fragment to the currently active call without checking that identifier. Out-of-order or malformed events could therefore associate arguments with a different tool call.

Description & Review Guide

• What are the major changes? Normalize the supported tool-call ID field names, ignore argument fragments whose ID does not match the active call, and clear call state only for the matching TOOL_CALL_END.
• What is the impact of these changes? Valid event streams keep their existing behavior. Mismatched fragments are ignored instead of being rebound to another call.
• What do you want reviewers to focus on? The matching rules when an event omits its ID, which preserve compatibility with streams that do not repeat the ID on every event.

Validation completed from python/:

• uv run pytest -q packages/ag-ui/tests/ag_ui/test_event_converters.py packages/ag-ui/tests/ag_ui/test_ag_ui_client.py (45 passed)
• uv run ruff check ...
• uv run ruff format --check ...
• uv run poe pyright -P ag-ui
• uv run poe test-typing -P ag-ui

Related Issue

Not linked yet.

Contribution Checklist

• The code builds clean without any errors or warnings
• All unit tests pass, and I have added new tests where possible
• The PR follows the Contribution Guidelines
• This PR is linked to an issue and there is no other open PR for this issue (see Related Issue above).
• This is not a breaking change. If it is a breaking change, add the breaking change label (or add "[BREAKING]" to the title prefix, before or after any language prefix) — a workflow keeps the label and title prefix in sync automatically.

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Adds safeguards to prevent TOOL_CALL_ARGS events from being incorrectly associated with the “current” tool call when IDs mismatch, with regression tests covering the expected behavior.

Changes:

• Ignore TOOL_CALL_ARGS when toolCallId doesn’t match the active tool call ID (and log a warning).
• Update tool-call end handling to conditionally clear current tool state based on matching IDs.
• Add tests to ensure mismatched IDs don’t rebind arguments or execute the wrong client tool.

Reviewed changes

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

File	Description
python/packages/ag-ui/agent_framework_ag_ui/_event_converters.py	Adds toolCallId mismatch checks for TOOL_CALL_ARGS and conditional state reset on TOOL_CALL_END.
python/packages/ag-ui/tests/ag_ui/test_event_converters.py	Adds regression test ensuring mismatched TOOL_CALL_ARGS don’t attach to the wrong tool call.
python/packages/ag-ui/tests/ag_ui/test_ag_ui_client.py	Adds client-level regression test ensuring mismatched args don’t cause execution of the current tool.

[moonbox3]

Please link the PR to an open issue

[github-actions]

Python Test Coverage Report •

File	Stmts	Miss	Cover	Missing
packages/ag-ui/agent_framework_ag_ui
_event_converters.py	110	1	99%	169
TOTAL	44137	5265	88%

Python Unit Test Overview

Tests	Skipped	Failures	Errors	Time
8842	33 💤	0 ❌	0 🔥	2m 23s ⏱️