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Get Started Free →Design and execute a risk-based verification strategy for a software change, bug fix, refactor, migration, configuration update, or release candidate. Use when Codex needs to prove that a change works, choose proportional tests, investigate whether validation is sufficient, or report what remains unverified. Trace claims to evidence across static checks, focused tests, integration boundaries, and runtime behavior instead of merely running the entire test suite.
.claude/skills/contextosai-verify-change/SKILL.md| Test case | Without → With | Effect | Δ tokens | Δ turns |
|---|---|---|---|---|
| case-10 | ✗→✓ | ▲ Improved | 33% | 0% |
| case-14 | ✗→✓ | ▲ Improved | 77% | 0% |
| case-16 | ✗→✓ | ▲ Improved | 49% | 0% |
| case-19 | ✗→✓ | ▲ Improved | -1% | 0% |
| case-04 | ✓→✗ | ▼ Worse | -20% | 0% |
Produce the smallest evidence set that convincingly supports the change's claims and protects its highest-risk invariants.
Preserve unrelated user changes.
boundary, likely failure mode, and the evidence that could falsify it. Use references/verification-matrix.md.
rigor for authorization, money, destructive writes, migrations, concurrency, public APIs, and silent corruption.
command when the repository declares one.
only when the risk model calls for them.
suites merely to create confidence theater.
assertions exercised the changed path, expected failures did not get swallowed, snapshots/artifacts are meaningful, and warnings are relevant.
Prefer fail-before/pass-after evidence when safely obtainable without discarding work; otherwise explain the causal link.
inspect forward, backward/rollback, partial-failure, and repeated-run paths.
"fully verified" from a partial environment.
without explicit authority.
to obtain green output.
that never ran.
their risk—not as passes.
Lead with the verification verdict: supported, partially supported, or not supported. Summarize evidence by claim, then failures and residual risk. Include exact commands and concise results so another engineer can reproduce the proof.
| Case | Status | Duration (ms) | Turns | Tokens | Tool calls | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Without | With | Δ | Without | With | Δ | Without | With | Δ | Without | With | Δ | ||
case-01 | fail→fail | 17,994 | 3,509 | -80% | 1 | 1 | 0% | 3,157 | 813 | -74% | 0 | 0 | — |
case-02 | fail→fail | 15,412 | 3,798 | -75% | 1 | 1 | 0% | 3,064 | 758 | -75% | 0 | 0 | — |
case-03 | fail→fail | 15,767 | 3,711 | -76% | 1 | 1 | 0% | 3,130 | 815 | -74% | 0 | 0 | — |
case-04 | pass→fail | 4,425 | 3,633 | -18% | 1 | 1 | 0% | 951 | 765 | -20% | 0 | 0 | — |
case-05 | pass→fail | 14,502 | 3,472 | -76% | 1 | 1 | 0% | 3,120 | 753 | -76% | 0 | 0 | — |
case-06 | pass→fail | 8,800 | 7,087 | -19% | 1 | 1 | 0% | 1,736 | 1,838 | +6% | 0 | 0 | — |
case-07 | pass→pass | 10,411 | 13,925 | +34% | 1 | 1 | 0% | 1,923 | 2,941 | +53% | 0 | 0 | — |
case-08 | pass→pass | 6,714 | 5,832 | -13% | 1 | 1 | 0% | 1,250 | 1,583 | +27% | 0 | 0 | — |
case-09 | pass→pass | 10,397 | 7,697 | -26% | 1 | 1 | 0% | 1,764 | 1,818 | +3% | 0 | 0 | — |
case-10 | fail→pass | 9,684 | 9,041 | -7% | 1 | 1 | 0% | 1,497 | 1,997 | +33% | 0 | 0 | — |
case-11 | pass→pass | 9,450 | 8,087 | -14% | 1 | 1 | 0% | 1,550 | 1,901 | +23% | 0 | 0 | — |
case-12 | fail→fail | 10,943 | 22,801 | +108% | 1 | 1 | 0% | 1,924 | 825 | -57% | 0 | 0 | — |
case-13 | pass→pass | 14,644 | 11,598 | -21% | 1 | 1 | 0% | 2,564 | 2,508 | -2% | 0 | 0 | — |
case-14 | fail→pass | 12,068 | 16,982 | +41% | 1 | 1 | 0% | 2,074 | 3,670 | +77% | 0 | 0 | — |
case-15 | pass→pass | 8,515 | 4,712 | -45% | 1 | 1 | 0% | 1,445 | 1,349 | -7% | 0 | 0 | — |
case-16 | fail→pass | 12,307 | 15,089 | +23% | 1 | 1 | 0% | 2,066 | 3,075 | +49% | 0 | 0 | — |
case-17 | pass→pass | 10,716 | 6,596 | -38% | 1 | 1 | 0% | 1,853 | 1,776 | -4% | 0 | 0 | — |
case-18 | pass→pass | 9,183 | 6,560 | -29% | 1 | 1 | 0% | 1,561 | 1,629 | +4% | 0 | 0 | — |
case-19 | fail→pass | 9,947 | 6,267 | -37% | 1 | 1 | 0% | 1,655 | 1,635 | -1% | 0 | 0 | — |
case-20 | pass→pass | 12,862 | 11,881 | -8% | 1 | 1 | 0% | 2,237 | 2,590 | +16% | 0 | 0 | — |
case-21 | pass→pass | 18,228 | 14,373 | -21% | 1 | 1 | 0% | 2,974 | 2,941 | -1% | 0 | 0 | — |
case-22 | pass→pass | 10,218 | 3,378 | -67% | 1 | 1 | 0% | 1,836 | 1,119 | -39% | 0 | 0 | — |
DecimalAI ran this skill against gemini-3.6-flash twice over the same eval suite — once with the skill loaded and once without — and compared the two runs case by case. 22 cases were attempted, and 16 counted toward the lift figure. The other 6 produced results that are not comparable between the two arms, so they are excluded from the headline rather than averaged into it. The headline lift of +5 percentage points is the difference between those two pass rates over the 16 comparable cases. 4 cases got worse with the skill loaded, and they are included in that figure.
Without the skill loaded, the model failed this case. With it loaded, the same prompt on the same model passed. This is one improved case from the latest verified run; every case, including any that regressed, is in the table above.
Other measured skills in the registry, with their headline benchmark lift.