Conciseness

Mostly efficient — the URL-pattern table, hreflang rules, TMS payoff threshold ("pays off above ~10K words"), and failure patterns are dense, non-obvious guidance. But Layer 5 re-explains facts Claude already knows: "thousand separators and decimals differ. 1,000.50 in en-US is 1.000,50 in de-DE", "Most of the world is metric; the US is imperial", and "Arabic, Hebrew, Persian, Urdu" as RTL languages. This fits 'Mostly efficient but includes some unnecessary explanation or could be tightened' rather than level 2, since the padding is confined to one section and each item is brief, and rather than level 4, because several paragraphs there could simply be cut.

Actionability

Guidance is mostly concrete and executable: a decision table with a stated default ("For most sites: subfolder is the default"), a copy-paste-ready hreflang snippet, specific workflow deliverables, and per-failure fixes ("Use CSS logical properties"). Minor gaps keep it below 5 — e.g., "hreflang links are valid (use a checker)" names no tool or command, and there is no sitemap hreflang example despite "Sitemap is best for large sites".

Workflow Clarity

The 10-step workflow is clearly sequenced from locale selection through maintenance, with a concrete test checklist in Step 8 ("hreflang links are valid", "Canonicals are self-referential per page", "RTL layout is correct") and monitoring metrics in Step 9. This fits 'Clear sequence with most checkpoints present; minor validation gaps' — Step 8 is a validation checkpoint but there is no explicit fix-and-retest feedback loop, and validation only appears after all implementation steps, so the anchor for 5 (explicit feedback loops for error recovery) is not fully met.

Progressive Disclosure

The body is an overview (framework, workflow, failure patterns) with the per-locale detail correctly split into a single reference that is real, one level deep, and clearly signaled with a description of its contents: "[`references/locale-checklist.md`](references/locale-checklist.md): Per-locale checklist of everything that needs to adapt beyond translation, organized by category". This matches 'Clear overview with well-signaled one-level-deep references; content appropriately split; easy navigation'.

Specificity

The description lists multiple specific concrete actions — "adding new locales, choosing URL structure for languages (subfolders vs subdomains vs ccTLDs), implementing hreflang, planning translation workflow, handling currency and date formats, designing for RTL languages, or auditing a stalled internationalization rollout" — with comprehensive coverage of the skill's scope. It fits the anchor 'Lists multiple specific concrete actions; comprehensive coverage' and is not the level below, which only allows minor gaps in coverage.

Completeness

It explicitly answers 'what' ("Plan and run a multi-language or multi-region site") and 'when' with concrete trigger phrases ("Use this skill when adding new locales... Triggers on... Also triggers when international audiences underperform or translations are stale"). This matches the anchor 'Clearly and explicitly answers both what AND when with concrete trigger phrases'; a missing or weak 'when' clause would cap it at 3, which does not apply.

Trigger Term Quality

Trigger coverage is comprehensive including synonyms and abbreviations users actually say: "internationalization, i18n, localization, l10n, hreflang, multi-language, translation workflow, RTL, locale, ccTLD, subfolder vs subdomain, language switcher". This matches the anchor 'Comprehensive coverage of natural terms including synonyms'; level 4 would require noticeably missing natural terms, which is not the case.

Distinctiveness Conflict Risk

The niche is clear and triggers are distinct to internationalization (hreflang, ccTLD, RTL, locale, language switcher), so the risk of firing for the wrong skill is minimal. It matches the anchor 'Clear niche with distinct triggers; minimal conflict risk' rather than level 4, which presumes minor overlap risk with closely related skills.