Genliang Zhu and colleagues study what a tool-using agent should do after a timeout leaves a remote action’s outcome uncertain. A retry can duplicate an effect that already happened or is still in flight.
Their controller considers evidence, waiting, valid deduplication keys, compensation and human handoff. A shared safety check rejects actions that would violate the modeled contract in any compatible state.
- On 37 modeled assignments, the planner and three simpler active policies each certified 28 safe completions. Planning saved four synthetic fee units against capability rules while using more computation.
- In a separate test of two local models, planner advice certified 30 of 58 paired cases versus nine with evidence prompting. Both conditions used the same safety check. The study did not compare planner advice against advice from simpler rules.
- The held-out cases were assignments within previously developed task families. The authors independently replayed trajectories against the same specification; this was not an external replication.
Caveat: The planner receives a supplied finite model of possible provider behavior. The results do not establish exactly-once execution against arbitrary services, or a production cost saving.