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The Driftproof receipt for find-skills on Claude Opus 5.5, dated 2026-10-18, and what it can say.

find-skills on claude-opus-5-5

Run on 2026-10-18, runner 0.22.2, surface claude-cli, verification level TESTED.

Regressed

A case separated downward under the band rule. That is a separation detected under the rule, not proof that the skill moved the score.

driftproof badge: regressed on claude-opus-5-5, 2026-10-18

The two arms

armmeanspread across casescases
with the skill0.889± 0.1213
without the skill0.891± 0.1103

Lift -0.002, ± 0.163. 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.

The two arms of this receipt drawn as ranges, with the effect floor marked. 0 0.25 0.5 0.75 1 overlapping without the skill 0.891 with the skill 0.889

What was verified

receipt_hash verified when this page was built from receipts/skill-measurements/published/187239fa2ebd8c19086d7df704d4a4da2c6d433ca974f9143ae7ac12a1ebe481.json; run.transcripts records retained-local.

Receipt hash: ae40fa3f5a12a6d72d93f6ebfc0a456757297886a88224e942022166aee945b4

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/skill-measurements/published/187239fa2ebd8c19086d7df704d4a4da2c6d433ca974f9143ae7ac12a1ebe481.json

npx driftproof@0.22.4 validate 187239fa2ebd8c19086d7df704d4a4da2c6d433ca974f9143ae7ac12a1ebe481.json

Embed the badge

[![driftproof](https://driftproofhq.com/r/ae40fa3f5a12a6d72d93f6ebfc0a456757297886a88224e942022166aee945b4/badge.svg)](https://driftproofhq.com/r/ae40fa3f5a12a6d72d93f6ebfc0a456757297886a88224e942022166aee945b4/)