Agents are pretty good at fixing integration bugs now. They're even better at sounding like they did.
The failure mode I kept hitting: a confident summary of a fix that didn't happen. Or a fix that made the symptom disappear while the data stayed wrong. Swallow the exception, error goes away, test goes green, customer still can't access what they paid for.
So we stopped taking the agent's word for it. Three things now get verified server side:
- Did the app actually run in both states (buggy and fixed)?
FetchSandbox MCP
