The Driftproof receipt for AGENTS.md on Claude Sonnet 5.5, from Report 016, dated 2026-10-28, and what it can say.
AGENTS.md on claude-sonnet-5-5
Passing
A case separated upward under the band rule. That is a separation detected under the rule, not proof that the skill moved the score.
Skill token cost: -481 input and -492 output tokens per call against no skill (measured, grading excluded).
The two arms
| arm | mean | spread across cases | cases |
|---|---|---|---|
| with the skill | 0.998 | ± 0.010 | 19 |
| without the skill | 0.987 | ± 0.057 | 19 |
Lift +0.011, ± 0.058. A spread is the sample standard deviation of the per-case means: a descriptive spread with no coverage probability. The verdict above reads each case's two bands, not these aggregates.
What was verified
receipt_hash verified when this page was built from receipts/report-016/receipt-3f4e17a1a3e0.json; run.transcripts records retained-local.
Receipt hash: 3f4e17a1a3e0b69d1b7e421b2a8c85de913f4d1cf244720eada82e82a05869f0
Check this file yourself
validate shows that this file is unchanged since it was sealed. It does not show who made it or who sealed it.
curl -fsSLO https://raw.githubusercontent.com/driftproofhq/driftproof/main/receipts/report-016/receipt-3f4e17a1a3e0.json
npx driftproof@0.28.0 validate receipt-3f4e17a1a3e0.json