Conciseness

Nearly every section carries Paddle/Next.js-specific knowledge Claude cannot be assumed to know (effectiveFrom semantics, paused-subscription 400, the 30-minute renewal lock, canceled vs scheduledChange, event ordering), and the Supabase block is explicitly justified ("if your project already has equivalent helpers, use those instead"). It is not 5 because the ~70 lines of Supabase client boilerplate and the partial overlap between the pitfalls list and the inline code comments (e.g., ownership check explained twice) could be trimmed; it is well above 3 since no section explains generic concepts Claude already knows.

Actionability

The full `cancelSubscription` Server Action is copy-paste ready with numbered steps, concrete env vars, a specific error-code map (`subscription_locked_renewal`, `subscription_locked_pending_changes`), and a slim DTO return shape. The two deliberate abbreviations — the undo action's "Run the same auth and ownership checks" and the imported `getPaddleInstance` — are explicitly signaled and backed by the linked starter kit, so the guidance remains fully executable for the common cases; this matches anchor 5 rather than anchor 4's "minor gaps".

Workflow Clarity

The action is sequenced 1–6 (auth → ownership → cancel → revalidate → DTO → error handling) with explicit validation: ApiError handling with recovery messaging per code, the paused-status branch, and a 7-step "Verify the integration" checklist including negative tests (logged-out request, forged subscriptionId) with expected return values. Since this destructive-capable operation has thorough validation and feedback loops, it satisfies anchor 5; the anchor-4 profile ("minor validation gaps") does not apply.

Progressive Disclosure

The body is well-organized with clear headers (When to use, Prerequisites, How it works, Full action, Undo, Pitfalls, Verify, Related docs) and clearly signals sibling skills and external docs. It is not 5 because this ~250-line SKILL.md is entirely monolithic — the Supabase helper setup and the customer-portal/Retain alternatives are natural candidates for a references/ file — and the guideline's 5-without-bundle-files exception applies only to skills under 50 lines. It is not 3 because structure and navigation are genuinely good, not merely present.

Specificity

"Cancel a Paddle subscription from a Next.js Server Action — auth, ownership check, safe `effectiveFrom` default, revalidation, and the `canceled` vs `scheduledChange` distinction" names the domain plus five concrete capabilities that map exactly to the skill's body sections. Coverage is comprehensive for the skill's scope, matching the anchor-5 example's density of specific actions; it is not score 4 because no capability area of the skill is left uncovered.

Completeness

The "what" is explicit and concrete (cancel via Server Action with auth, ownership check, safe effectiveFrom, revalidation, status distinction), but there is no "Use when..." clause or equivalent explicit trigger guidance — the "when" is only weakly implied by "from a Next.js Server Action". Per the rubric guideline, a missing 'Use when' clause caps completeness at 3, which fits anchor 3 (clear 'what', weakly implied 'when') exactly; it cannot be 4 without explicit trigger phrasing.

Trigger Term Quality

Natural terms a user would say are present: "Cancel a Paddle subscription", "Next.js Server Action", "auth", "revalidation". It is not 5 because common user phrasings like "unsubscribe", "end/cancel my subscription button", or "billing page" are absent; it is not 3 because the core natural vocabulary ("cancel subscription", "Paddle", "Next.js") is fully covered rather than only partially.

Distinctiveness Conflict Risk

"Paddle subscription" + "Next.js Server Action" + "cancel" is a clear niche with distinct triggers and minimal conflict risk; even sibling Paddle skills (sync, webhooks, portal) would not be wrongly triggered by a cancel request. It clearly matches anchor 5 rather than anchor 4, which implies residual overlap risk with closely related skills.