Conciseness

The body is dense and efficient - decision tables, hard-stop sequencing, a worked example, and an anti-pattern table with almost no filler. A few tokens could be trimmed: the Wikipedia definition of Simpson's paradox and 'A 95% confidence interval gives the plausible range of the true effect' re-teach concepts Claude already knows, and inline '(Nielsen Norman Group, [sources](references/sources.md))' citations repeat. Fits 'efficient; minor instances of over-explanation' rather than the lean-every-token-earns-its-place anchor at 5.

Actionability

Guidance is concrete and decidable throughout: a CI-position-to-interpretation table, hard numeric rules ('do not ship on a positive aggregate with a negative segment that represents > 20% of users', 'minimum run time: two full weeks'), alert-vs-block threshold semantics, and a fully worked numeric example (+1.2pp lift, CI +0.3/+2.1pp) covering the common case. Per the rubric's scoring note, absence of code in an instruction-only skill is not penalized when the guidance is actionable, which it fully is.

Workflow Clarity

The six steps are explicitly ordered with a stated control flow ('Each step has a hard stop: if a step blocks, do not proceed to the next'), each step carries its own validation criteria, and the worked example walks all six in sequence. This is a decision workflow rather than a destructive/batch operation, so the workflow-clarity cap does not apply; it matches the top anchor (explicit checkpoints, error-recovery guidance via the anti-patterns table).

Progressive Disclosure

The SKILL.md body stays at interpretive-overview altitude and splits deep methodology into four real, clearly-signaled reference files (peeking.md, guardrails.md, thresholds-and-corrections.md, sources.md), each link annotated with its content and all verified to exist one level deep. Matches the 'clear overview with well-signaled one-level-deep references' anchor.

Specificity

The description enumerates six concrete interpretation capabilities (practical vs statistical significance, CI reading, novelty/primacy decay, interaction effects, Simpson's paradox, ordered guardrail checks) plus the deep-dive topics in references/. It matches the 'multiple specific concrete actions; comprehensive coverage' anchor; not 4 because there are no meaningful coverage gaps, and it uses proper third-person voice ('Interprets', 'Covers').

Completeness

Both questions are answered explicitly: the 'what' is the enumerated interpretation capabilities, and the 'when' is a concrete 'Use when...' clause ('ready to draw conclusions from an experiment, when designing a stop-early policy, or when declaring an experiment's guardrail set'). This matches the top anchor exactly; not 4 because the triggers are concrete, not merely present.

Trigger Term Quality

Good natural-language coverage ('experiment', 'draw conclusions from an experiment', 'ship decision', 'stop-early policy', 'guardrail'), but the most common user phrasing 'A/B test' appears only in metadata keywords, not in the description itself. Fits the 'good keyword coverage; a few natural terms missing' anchor rather than the comprehensive-synonyms anchor at 5.

Distinctiveness Conflict Risk

It carves out a clear niche and explicitly disambiguates from the closest neighbor ('Distinct from ab-test-validity-checklist (harness setup and SRM detection)') and scopes its premise ('one whose harness, SRM, and telemetry have already been confirmed'). Minimal conflict risk; the 5 anchor fits better than 4.