Chapter 21: Failure drills
Break one part on purpose and watch the result. Remove a skill description. Return a large tool output. Remove the step cap. Loosen the fingerprint. Remove the citation check. Record the eval score before and after each drill, then revert.
| Drill | What it breaks | Built in |
|---|---|---|
| Remove a skill description | Skill selection and the model’s choice | Chapter 14, Chapter 15 |
| Return a large tool output | A small parent context | Chapter 18 |
| Remove the step cap | The STEP_LIMIT stop | Chapter 6 |
| Loosen the fingerprint | Duplicate suppression and the triage cache key | Chapter 20, Chapter 22 |
| Remove the citation check | Cited answers | Chapter 12 |
Table 21.1. Each drill undoes one earlier chapter. The middle column is a teaching guide; the eval score is the real measure.