Conciseness

The body is mostly efficient (tables, checklists, templates earn their tokens), but it includes a stats-101 primer on p-values and confidence intervals that Claude already knows, repeats the anti-peeking warning in three places (Core Principles, "Avoid," and its own section), and duplicates sample-size tables that also exist in the reference file — more than the minor trimming of anchor 4, fitting anchor 3.

Actionability

The guidance is fully executable for an instruction-only skill: a copy-paste hypothesis template with weak/strong examples, a numeric sample-size quick-reference table, a concrete metrics example (pricing page test), named tools per implementation approach, ICE formula, a fill-in playbook template, and pre-launch/analysis checklists — matching anchor 5's coverage of common cases.

Workflow Clarity

The test lifecycle is clearly ordered (Initial Assessment → Hypothesis → Design → Pre-Launch checklist → During the Test → Analysis checklist → Documentation) with checklist checkpoints and a guardrail stop rule ("do stop tests where guardrails are significantly negative"). However, the end-to-end sequence is implied by section order rather than stated explicitly, and error-recovery feedback loops are only partial (e.g., "Mixed signals → check data quality"), so it fits anchor 4 rather than anchor 5's explicit validate-fix-retry loops.

Progressive Disclosure

Two real, clearly signaled, one-level-deep references exist and match their in-body claims (sample-size-guide.md, test-templates.md), but substantial detail is still inline — a full 4×4 sample-size table alongside the reference file and an ~85-line Growth Experimentation Program section — matching anchor 4's "few key examples inline, bulk in separate file" rather than anchor 5's pointer-style split.

Specificity

"plan, design, or implement an A/B test or experiment, or build a growth experimentation program" lists several actions covering both single tests and program-building, but the verbs are generic and capabilities like sample-size calculation and significance analysis are only implied through triggers — several specific actions with minor gaps (anchor 4), not the comprehensive distinct operations of anchor 5.

Completeness

It explicitly answers "what" (plan, design, implement A/B tests; build a growth experimentation program) and "when" through multiple explicit clauses ("Also use when the user mentions...", "Use this whenever someone is comparing two approaches..."), with concrete trigger phrases plus boundary routing ("For tracking implementation, see analytics. For page-level conversion optimization, see cro.") — a clear anchor 5 match.

Trigger Term Quality

The trigger list is comprehensive and natural — "A/B test," "split test," "multivariate test," "should I test this," "which version is better," "test two versions," "how long should I run this test," "ICE score," "experiment playbook" — covering synonyms, user-phrased questions, and program-level terms, matching anchor 5's comprehensive natural-term coverage.

Distinctiveness Conflict Risk

The experimentation niche is clear and adjacent skills are explicitly disambiguated (analytics, cro), but broad triggers like "experiment," "hypothesis," and "test this change" carry minor overlap risk with general testing or statistics contexts — mostly distinct with minor overlap (anchor 4) rather than the minimal-conflict anchor 5.