The Driftproof receipt for CLAUDE.md on Claude Sonnet 5.5, from Report 016, dated 2026-10-28, and what it can say.
CLAUDE.md on claude-sonnet-5-5
Not enough draws
Not enough draws to conclude at this effect floor.
Lost draws: case deep-merge-js lost 1 of 4 with-skill draws (incomplete_evidence). Neither a separation nor its absence is shown to hold for every score the lost draws could have had, and a draws-needed count would assume their scores, so none is given.
Skill token cost: +7608 input and +210 output tokens per call against no skill (measured, grading excluded).
The two arms
| arm | mean | spread across cases | cases |
|---|---|---|---|
| with the skill | 0.987 | ± 0.057 | 19 |
| without the skill | 0.989 | ± 0.048 | 19 |
No lift is stated for a state that did not measure one. 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-d1d24d545bb8.json; run.transcripts records retained-local.
Receipt hash: d1d24d545bb81c87b41bf8fec7c7f372e45621301dbcf2f18ea0327719df925b
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-d1d24d545bb8.json
npx driftproof@0.28.0 validate receipt-d1d24d545bb8.json