The Driftproof receipt for tdd on Claude Sonnet 5.5, dated 2026-11-08, and what it can say.
tdd 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: +1160 input and +34 output tokens per call against no skill (measured, grading excluded).
The two arms
| arm | mean | spread across cases | cases |
|---|---|---|---|
| with the skill | 0.986 | ± 0.013 | 3 |
| without the skill | 0.946 | ± 0.094 | 3 |
Lift +0.040, ± 0.095. 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/canary/2026-11-08/tdd-claude-sonnet-5-5-2026-11-08-9ca6bc6c1a10.json; run.transcripts records hashes-only.
Receipt hash: 9ca6bc6c1a104662179f0deb5412145238275f6a792bc290ab727303d370ef2c
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/canary/2026-11-08/tdd-claude-sonnet-5-5-2026-11-08-9ca6bc6c1a10.json
npx driftproof@0.28.0 validate tdd-claude-sonnet-5-5-2026-11-08-9ca6bc6c1a10.json