Building a Public Backlog of AI Agent Failures: What's the Worst Thing Your Tests Didn't Catch?

Not looking for a highlight reel of prompt injection screenshots, more interested in the mundane stuff: the agent that called the wrong tool with confidently valid-looking arguments, the multi-turn conversation that drifted somewhere nobody planned for by turn six, the endpoint that worked fine in every test case and then did something strange the first week it saw real traffic. If you've shipped an agent, something has probably slipped through. A few prompts in case they help: What kind of…