You'll notice
Refused cross-machine tool calls now explain why: stale, queue full, rate limited, duplicate, withdrawn or result lost.
The refusal-reason map for remote, cross-machine tool calls gained several new cases beyond the prior generic ones: stale, queue_full, rate_limited, duplicate_call, withdrawn, and result_lost, each with a human-readable explanation (for example queue_full reports "that machine was at one of its capacity limits"). These surface when a call to another machine in a session is refused.