Asked about Designing so failure is survivable

How do you confirm an agent actually completed a task?

An answer that works

Verify against the world in code, not by asking the model. Check that each required side effect happened. Asking the agent uses the same process that produced any mistake, so it will report success either way.

Reading an answer is not being able to give one. The section that teaches this is Designing so failure is survivable, 5 hours of Agent reliability.

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