Conciseness

The body is dense and efficient: tables instead of prose, no tutorials on what A/B testing is, and every step is a terse gate. Two minor instances of trimmable over-explanation keep it off the 5 anchor: "An SRM means the observed split differs from the configured one..." (Claude knows this) and the one-line explanation of what scipy.stats.chisquare takes and returns.

Actionability

Fully executable, copy-paste-ready guidance: a complete srm_check.py with a usage comment and exit-code contract, a worked example ("For 503,000 / 497,000 at 50/50: chi2 = 36.0, p ≈ 2e-9, so SRM"), concrete file paths (experiments/<id>/proposal.yml, checklist.md, result.md), and specific pass criteria in every gate table.

Workflow Clarity

Steps 1-7 are explicitly sequenced as gates with named checkpoints (Step 1 reviewer confirmation, Step 4 A/A-day validation) and a real feedback loop: on SRM, work the five root-cause stages, fix, re-run srm_check.py, and "continue only on exit code 0", with "Any failed gate means no-ship or extend, never ship with a note" closing the process.

Progressive Disclosure

Verified against the actual bundle: the single reference (references/checklist-template.md) exists, is one level deep, and is clearly signaled both in the Overview ("from [references/checklist-template.md]") and in the References section. The body keeps the process inline and pushes only the fill-in form to the reference, with well-organized sections (Overview, When to use, Steps, Anti-patterns, Limitations, References) for easy navigation.

Specificity

The description gives one core concrete action ("Builds a per-experiment checklist and sign-off") with a comprehensive enumerated list of concrete components ("pre-registered metric, power and guardrails, randomization unit and sample ratio mismatch checks, assignment, telemetry, peeking rules and novelty effects"). Not the 5 anchor because it is a single verb with a content list rather than multiple distinct actions like "extract text, fill forms, merge documents".

Completeness

It explicitly answers both: "Use when launching, auditing or governing an A/B test or online experiment design" (explicit when with concrete triggers) and "Builds a per-experiment checklist and sign-off: ..." (clear what with concrete contents). Matches the anchor for clearly and explicitly answering both.

Trigger Term Quality

"launching, auditing or governing an A/B test or online experiment design" plus "checklist", "sign-off", "guardrails" and "sample ratio mismatch" are natural phrases users would say in this domain. Not 5 because common variations like "split test", "experiment results" or "ship decision" are missing; not 3 because coverage clearly goes beyond a bare domain mention.

Distinctiveness Conflict Risk

The validity-checklist/sign-off niche is distinct and the A/B-testing vocabulary is specific, so conflicts with generic skills are unlikely. Not 5 because "auditing" an experiment and the guardrail/peeking mentions slightly overlap the sibling experiment-reading skills referenced in the body.