Verify Behavior

Given a behavioral claim about code, or a change that was just applied, decide the cheapest way to get executed proof, run it in isolation, and report the raw result as a receipt.

This skill is the execution engine six-plus call sites in this repo used to hand-roll independently: "detect the toolchain, run something, read pass or fail." It replaces the ad hoc version in each of those with one shared ladder.

This SKILL.md is a thin index. Detailed rules live in rules/*.md and load on demand.

The execute-not-score boundary

This skill does not score — it never assigns a confidence score and never grades pass/fail against an intent. It runs a command, captures the raw output, and classifies the result against the claim itself as confirms / contradicts / ambiguous / null.

• confidence(code) owns the number — this skill supplies sharper evidence to that gate, it does not replace it.
• A calling agent's own grading (e.g. bug-fix-verifier's FAIL_TO_PASS, the aw-executor Phase 4 expect comparison) stays with the caller — this skill supplies the run-and-observe mechanic underneath that grading, not the grading itself.