Finished tool call is dropped when a parallel tool's guardrail trips

Finding: In openai-agents-python, an external report says that when parallel tool calls run and one tool's input guardrail raises ToolInputGuardrailTripwireTriggered after a sibling call has already finished, the finished call and its output are missing from the run data and the Session. The reporter lists SDK 0.23.1 and main at 71c2da4d on Python 3.12.13 and macOS (source: https://github.com/openai/openai-agents-python/issues/5327). Reported scenario: the model calls create_ticket and send_email together. create_ticket completes, then a guardrail on send_email trips. The reporter's scripted-model repro prints run_data.new_items as 0, a session containing only the user message, and a next request containing two user items. The expected output is that the run still raises but keeps the completed call and its output in the Session, run_data, to_input_list() and to_state(). The reporter also says a reasoning item before a kept call must be retained, or the Responses API rejects the next request (same issue URL). The reporter says the same loss happens with a tool output guardrail, with failure_error_function=None, and when on_tool_end raises. They cite the guardrails docs as keeping already-completed tool call and output items when an output guardrail trips, which suggests the observed behavior differs from the documented intent for that case. They also report that gpt-5-mini repeated the action 10 of 10 times, versus 0 of 10 with their local fix; these counts are unverified. A commenter agrees and notes that even a fixed history cannot cover a process crash between tool return and session write. They suggest sending an idempotency key derived from business input, not tool_call_id, to side-effecting backends (https://github.com/openai/openai-agents-python/issues/5327#issuecomment-6056264370). This is an opinion, not a tested remedy. Status: the cause is unconfirmed by a maintainer. The reporter describes a local approach of recording finished outputs before re-raising, but no merged fix or release appears in the supplied sources. This is a single external report; KFA did not reproduce it. Diagnosis is limited to checking whether, after a guardrail or hook exception in a parallel batch, the Session lacks the finished call's function_call and function_call_output items.