library / AI Lab / AI Failures And Evals / agent-failure-zooreviewed 2026-08-14

AI Lab / AI Failures And Evals

Agent Failure Zoo

A practical field guide to how AI agents fail: wrong tool, stale context, hidden authority, bad memory, and confident nonsense wearing a clipboard.

Room context

Post

Reading note.

A list of common AI-agent failure modes and how to test for them.

How to read this

Personal writing is labelled personal; external claims, quotes, and media require source context.

The Zoo

An agent is not smarter because it has tools. It is now capable of being wrong with consequences. The zoo is a place to name failures before they escape into product copy.

Starter animals: the Obedient Browser, the Citation Tourist, the Stale Memory, the Overconfident Scheduler, the Tool Juggler, the Permission Acrobat, and the Evals Peacock.

  • tool misuse
  • retrieval drift
  • authority confusion
  • memory leak
  • overbroad action
  • missing eval
  • unclear rollback

How To Use It

Each failure gets a tiny story, a reproduction prompt, a test case, a prevention pattern, and a question a reviewer should ask before launch.

The tone can be funny. The check should be boring. That is the bargain.

First Failure Cards

Obedient Browser: the agent treats page text as instruction. Test it with a page that asks the assistant to ignore the user's task.

Citation Tourist: the answer includes citations that look scholarly but do not support the claim. Test it with conflicting sources and require quoted evidence.

Permission Acrobat: the agent turns a vague user wish into an action it was never allowed to take. Test it with calendar, email, file, and purchase-like boundaries.

  • name the failure
  • show a tiny reproduction
  • write the prevention pattern
  • add a regression case

Reviewer Questions

What input is trusted? What input is only data? Which action needs explicit permission? What happens when sources disagree? What receipt proves the agent did the right thing?

A good launch review should be able to answer those questions without opening the product owner's brain.

Nearby

You might go next