Conciseness

Dense, table-driven content that assumes Claude's competence and explains only non-obvious domain material, with minor trimmable redundancy: the References section re-lists URLs already tabulated under "Data sources for traffic share", and there is cross-reference chatter like "The single authoritative traffic thresholds, referenced by the three-tier model and worked example above".

Actionability

Fully actionable for an instruction-only skill: exact thresholds (≥5%, 1-5%, <1%, <0.1%), a rules-based tier-membership heuristic, a cost-tier infrastructure mapping, a BLOCK/WARN review checklist with concrete rules, and a worked example with real numbers. Specific examples cover the common cases, matching the top anchor.

Workflow Clarity

The 8-step "How to use" sequence ends in an explicit validation gate ("assert traffic <0.1% across two independent sources... AND that no statutory or SLA requirement applies; if either check fails, keep the combo in T3 and re-review next quarter") — a validation step with an error-recovery feedback loop — complemented by the review checklist ("Refuse to treat a matrix as PASS while any BLOCK finding stands") and the quarterly re-run loop.

Progressive Disclosure

The bundle is well structured: three real reference files, all linked from the body, one level deep, and clearly signaled with their contents (e.g., the budget section enumerates what compatibility-budget.md "carries"). Minor gaps: compatibility-budget-tiers.md is linked only from the terminal References list rather than the budget section that describes its tier tables, and the budget section slightly misattributes where the tier definitions live.

Specificity

Names several concrete deliverables — "a three-tier matrix built from traffic data, quarterly re-tier reviews, a published support policy and test budget, or the case for dropping an old browser" — but they are framed as artifacts rather than a comprehensive set of concrete actions, and the closing sentence about sibling skills adds no capability.

Completeness

Explicitly answers both: "Use when deciding which browsers, OS versions and devices to test..." gives concrete trigger scenarios, and the what is stated as the three-tier matrix, re-tier reviews, support policy, test budget, and drop rationale. Not 4 because the when-clause is explicit and specific rather than merely present.

Trigger Term Quality

Natural phrases like "which browsers, OS versions and devices to test", "traffic data", "support policy", and "dropping an old browser" are present, but common variations such as "cross-browser testing" and "browser compatibility" are missing.

Distinctiveness Conflict Risk

Occupies a clear niche (matrix strategy vs. test execution) and explicitly disambiguates from the overlapping sibling skills via "The Playwright, Selenium Grid and cloud-grid skills run it", keeping conflict risk minimal.