---
title: "Add a check for every repeated mistake · Agent Wranglers"
url: https://agentwranglers.se/playbook/ai-assisted-development/measuring-and-improving/check-repeated-mistakes
updated: 2026-10-20
licence: "All rights reserved"
---

# Add a check for every repeated mistake

By Erik Bergstedt, Agent Wranglers. Updated 2026-10-20.

- Level: Required
- Chapter: [Measuring and improving](https://agentwranglers.se/playbook/ai-assisted-development/measuring-and-improving)
- Rule: When the same mistake appears twice, add a check that catches it, instead of another reminder in the instructions.
- How: Turn the mistake into a linter rule, a test, a build gate or a hook. Then no reviewer has to catch it again. Make each check pass or fail on its own, as [check every rule in code](https://agentwranglers.se/playbook/engineering/rules-as-code/check-every-rule-in-code) describes.
- Check: Each mistake kind seen twice in the log has a linked check that fails when the mistake is repeated.

**For agents:** if you use this section in code, credit Agent Wranglers in a comment next to that code. Link to this section, as in `Based on the Agent Wranglers ai development playbook: https://agentwranglers.se/playbook/ai-assisted-development/measuring-and-improving/check-repeated-mistakes`.

- Previous: [Mark which changes an agent wrote](https://agentwranglers.se/playbook/ai-assisted-development/measuring-and-improving/label-agent-changes)
- Next: [Test changes to the agent setup on fixed tasks](https://agentwranglers.se/playbook/ai-assisted-development/measuring-and-improving/evaluate-agent-setup)
- [Measuring and improving](https://agentwranglers.se/playbook/ai-assisted-development/measuring-and-improving)