Python: [Bug]: Orphaned mcp_call items cause HTTP 400 in multi-turn reasoning model flows

[csajmishra]

Description

Problem highlighted in below issue has not been resolved for customer.
#6074

Code Sample

Attached the code sample used by client. 
[run_maf_workflow.txt](https://github.com/user-attachments/files/29597439/run_maf_workflow.txt)
[run_workflow.txt](https://github.com/user-attachments/files/29597438/run_workflow.txt)

Error Messages / Stack Traces

HTTP 400 — Item 'mcp_<id>' of type 'mcp_call' was provided without its
required 'reasoning' item: 'rs_<id>'.

Package Versions

agent-framework==1.8.0

Python Version

3.13

Additional Context

Issue is INTERMITTENT — does not fire on every run. We need to try 5-6 times to reproduce.

[github-actions]

🤖 Automated triage reproduction notes (agent-authored — trust but verify)

Agent analysis

Repro: SlidingWindowStrategy in packages/core/agent_framework/_compaction.py orphans mcp_call from reasoning because (1) _output_item_to_message in packages/foundry_hosting/.../_responses.py:1381-1386 converts reasoning OutputItems via Content.from_text() instead of Content.from_text_reasoning(), and (2) _is_tool_call_assistant at _compaction.py:78 only checks for "function_call" not "mcp_server_tool_call". Minimal repro: annotate_message_groups on [system, assistant(text="Reasoning"), assistant(mcp_server_tool_call), tool(result), assistant(text), user] then apply SlidingWindowStrategy(keep_last_groups=4) — reasoning is removed while mcp_call remains.

• Failing test: python/packages/core/tests/core/test_orphaned_mcp_call_issue_6883.py
• Files examined: python/packages/core/agent_framework/_compaction.py, python/packages/foundry_hosting/agent_framework_foundry_hosting/_responses.py, python/packages/core/agent_framework/_types.py, python/packages/foundry_hosting/tests/test_responses.py, python/packages/core/tests/core/test_compaction.py
• Tests run: python/packages/core/tests/core/test_orphaned_mcp_call_issue_6883.py
• Reported version: 1.8.0
• Current version: 1.10.0