Vaccinate — grade the grader

Twenty bugs were once planted in a working codebase and the review agents were asked to check it again. They reported everything was fine. Recall: 0/20.

A vaccine is a small, controlled dose of error that strengthens the whole system. This skill administers one.

The rule it enforces: an unqualified check is not weak evidence — it is none.

When to run it

• Before a referee simulation, reproducibility gate, or review agent is used to make a decision that matters (a submission, a release, a deposit).
• After changing a checker — a modified gate is unqualified until re-measured.
• On a schedule for gates that guard load-bearing claims. Detection decays as artifacts drift.

Protocol