Reviewing code an AI agent wrote

A practical checklist for agent pull requests, from the tests to the things agents quietly skip.

An agent's pull request usually looks tidy and confident, with a summary saying everything is done. That is exactly why it needs a careful review. These are the checks we run on every agent change.

1. Start with the tests

  • Is there a test for each behaviour the issue asked for, and would it fail without the change?
  • Were any existing tests changed, weakened or deleted? If so, is the reason stated and right?
  • Does an assertion actually check something? Agents sometimes write tests that always pass.
  • Did the tests really run? Read the CI output, not the summary.

2. Check the scope

  • Does the change do what the issue asked, all of it, and nothing more?
  • Are unrelated "improvements" mixed in? Ask for them separately.
  • Is anything marked done in the description that isn't in the diff?

3. Look for quiet shortcuts

  • Errors swallowed, checks skipped, or a hook or test disabled to get a green build
  • Hard-coded values where configuration belongs
  • New dependencies nobody asked for
  • Copies of existing code instead of reuse
  • Comments that describe what the code should do rather than what it does

4. Security and data

  • No secrets, tokens or personal data in code, logs or test fixtures
  • Input from outside validated at the boundary
  • Anything that changes what is stored, logged or shared reflected in your privacy notes

5. Fit with your codebase

  • Names use your domain's terms, not near-synonyms the agent made up
  • The change follows your existing patterns and structure
  • Generated files such as database migrations were produced by your tools, not written by hand

Then improve the system

When a review finds a problem, fix the pull request, then ask why the agent made the mistake. Usually the answer is a missing instruction, a missing test or a missing automated check. Add it, and the next change starts from a better place.

Next: test-first with AI coding agents, or back to the AI Engineering Academy.