Verify the change
Ask the agent to prove the change actually works, by running it, testing it, or showing evidence, before it tells you it's done.
Require objective evidence that the change achieves its goal: re-running the original reproduction, running relevant automated tests, type checks, and the build, or a manual check, and reporting actual results rather than claims.
After a plumber fixes a leak, you turn on the tap and look under the sink. You don't just take "it's fixed" on faith.
Agents sometimes say "fixed" based on reading their own code, without running anything. Asking for verification, with the actual output, catches both real mistakes and success the agent only imagined.
Verified: the original reproduction now passes, all 34 checkout tests pass, and the build succeeds. The output is below.
Verify the change before telling me it's done: re-run the steps that reproduced the bug, run the related tests, and paste the actual output.
Accepting "I've fixed it" as verification. A claim isn't evidence. Ask what was run and what the output was.