Conciseness

The body is dense, curated domain guidance that assumes Claude's competence — it applies Hick-Hyman, PCI boundaries, and idempotency by reference without re-teaching them, and every section carries non-obvious specifics (Baymard coupon finding, Play promo code vs. merchant coupon). Minor trimming is possible: the neighbor-skill boundary declarations are restated across four sections (Governanca Global, Quando Não Usar, Handoff, Integração com Pipeline).

Actionability

As an instruction-only design skill it gives fully executable guidance: exact microcopy formats ("59,99€/ano · equivale a 5,00€/mês · Renovação anual até cancelamento."), exact touch targets ("48×48dp"), a named state machine ("Ready → Submitting → Authenticating (3DS) → Pending → Succeeded | Failed → Reconciling"), a concrete coupon pattern with copy ("🏷 Tem um cupão?"), a billing decision table, an event funnel, and a QA matrix. Per the rubric's instruction-only note, the absence of code is not penalized when guidance is this concrete.

Workflow Clarity

Sequencing is explicit (billing decision "antes de desenhar qualquer tela"; periodicidade before plan cards because it "reinterpreta o preço de todos eles"), with a labeled "**Checkpoint:**" requiring backoff re-query instead of inferring success/failure from silence, error-recovery feedback loops (preserve validated plan/coupon on payment error, retry or change method, idempotency key against double charge), and a 7-item "Evidência de Conclusão" checklist.

Progressive Disclosure

The SKILL.md is a genuine overview with well-signaled, one-level-deep references to seven numbered guide files, each annotated with exactly what it contains (e.g. "Detalhe completo (matriz por mercado, promo code Play vs. cupão de comerciante, tokenização/PCI, idempotência) em docs/skill-guides/mobile-paywall-checkout/01-billing-decision.md"). However, none of the referenced files — nor the cited skills/, policies/, or docs/ paths — exist in this bundle (no references/, scripts/, or assets/ directories), so the split into detail files cannot be verified or relied upon as shipped; this organization gap keeps it below the top anchor.

Specificity

"Projeta paywalls e checkout mobile com foco em clareza e conversao" names the domain and a single action verb, but the description omits the skill's other concrete capabilities (billing architecture decision, coupon UX, payment states, accessibility, A/B experimentation) that the body clearly covers. This matches the anchor for 1-2 concrete actions without comprehensive coverage; it is not 4 because it does not list several specific actions.

Completeness

Both parts are explicit: "what" ("Projeta paywalls e checkout mobile com foco em clareza e conversao") and "when" ("Trigger em:" followed by concrete phrases). It falls short of the top anchor only because the "what" is a single clause that undersells the skill's scope relative to its actual content; the "when" is fully explicit.

Trigger Term Quality

The trigger list is exhaustive (21 terms) with natural user phrases in both Portuguese and English ("tela de assinatura", "seleção de plano", "campo de cupão", "plano recomendado", "purchase sheet", "preço anual vs mensal") plus technical terms, synonyms, and abbreviations ("in-app purchase"/"iap", "3ds"/"3d secure"). This matches the comprehensive-coverage anchor including synonyms.

Distinctiveness Conflict Risk

The in-app mobile subscription checkout niche is clear and most triggers are distinctive ("google play billing", "purchase sheet", "billing period selector", "mercado pago mobile"). There is minor overlap risk with closely related skills the ecosystem itself acknowledges (public pricing page / general UI design), since generic terms like "paywall" and "preço anual vs mensal" could also apply to web pricing contexts.