Conciseness

The body is mostly tight and instructional, but it embeds time-sensitive version numbers (e.g., '2026-10-28.endive' hardcoded in ~8 code examples) outside any 'old patterns'/'deprecated' section — partially mitigated by the instruction to "Replace bundled API versions shown in those examples with the selected target" — and explains semantic versioning (MAJOR/MINOR/PATCH) that Claude already knows. This fits anchor 3 (mostly efficient with some unnecessary explanation or tightening possible) rather than 4.

Actionability

Concrete, executable guidance dominates: copy-paste-ready Python/Ruby/JS client config, a per-request override, a curl example with the Stripe-Version header, commands like "npm update stripe" and "pip install --upgrade stripe", and a very specific webhook-destination replacement procedure. Minor gaps keep it at anchor 4 rather than 5: no concrete commands for selecting Java/Go/.NET SDK releases or updating mobile SDKs.

Workflow Clarity

The 9-step Upgrade Checklist is clearly sequenced with real checkpoints: test via the Stripe-Version header before changing defaults, accept both signing secrets during testing and cutover, disable the old destination after cutover, and a 72-hour rollback window. It falls short of anchor 5 only because the validate -> fix -> re-test feedback loop is implied ("Test your integration") rather than explicitly spelled out.

Progressive Disclosure

No bundle files exist, and the ~190-line body is organized under clear section headers with deep detail delegated via clearly signaled, one-level-deep links to official Stripe docs (e.g., "See [Set a Stripe API version for your SDK](https://docs.stripe.com/sdks/set-version.md) for details"). This matches anchor 4 (good structure, most content appropriately placed); it is not 5 because per-SDK versioning sections (server-side, Stripe.js, mobile) could be split into reference files to keep SKILL.md a leaner overview.

Specificity

"Guide for upgrading Stripe API versions, webhook endpoints, server-side SDKs, Stripe.js, and mobile SDKs" names the domain and enumerates five concrete upgrade targets, but the sole action verb is "upgrading" — no additional concrete actions (compare pinned versions, migrate events, test) are stated. This matches anchor 3 (domain plus 1-2 concrete actions, not comprehensive) rather than 4, which requires several distinct specific actions.

Completeness

The description clearly answers "what" (a guide for upgrading Stripe API versions, webhook endpoints, and SDKs) but contains no "Use when..." clause or equivalent trigger guidance, which caps completeness at 3 per the judging guidelines. It is not 4 because "when" is entirely absent rather than present-but-imprecise.

Trigger Term Quality

"Stripe", "upgrading", "API versions", "webhook endpoints", "SDKs", "Stripe.js", and "mobile SDKs" are phrases users would naturally say when needing this skill. A few natural variations are missing (e.g., "update Stripe integration", "migrate Stripe", "bump API version"), so it fits anchor 4 (good keyword coverage, a few natural terms missing) rather than anchor 5's comprehensive synonym coverage.

Distinctiveness Conflict Risk

"Stripe" plus the enumerated components (API versions, webhook endpoints, server-side SDKs, Stripe.js, mobile SDKs) establish a clear niche with distinct triggers and minimal conflict risk with other skills, matching anchor 5. It is not below 5 because no generic or overlapping language appears.