"Done!" Is Not a Return Code: Why Agent Completion Needs a Structured Signal
An agent ends its turn with "All done — let me know if you want any changes!" and your orchestrator has to decide whether to mark the ticket resolved, kick off the next handoff, or retry. That sentence is not a return code. It is a polite closing line trained to sound reassuring at the end of a chat, and every line of automation downstream of it inherits the ambiguity. The teams that treat this as a parsing problem write regexes that catch \b(done|complete|finished)\b and call it a day. The teams whose agents run in production eventually learn that completion is an event, not a mood.
The failure mode is bimodal and boring. Either the agent announces done when it isn't — premature termination — and the orchestrator happily advances the workflow on a half-finished artifact. Or the agent is actually done, but phrases it in a way that doesn't match the detector ("I went ahead and landed the change, though the test for the edge case is still flaky"), and the orchestrator spins up a retry that re-does the work, duplicates the side effect, and sometimes contradicts the successful first pass. Both modes degrade silently. Neither shows up in a dashboard until someone reads a trace and notices that the agent said "I think that covers it" and the billing system treated that as a commit.
The fix is not smarter parsing. It is giving the agent a structured way to terminate — a done-tool with an enumerated status, a reason code, and a handle your pipeline can route on — and changing the orchestrator to wait for that event instead of listening to the chat stream.
