Conciseness

The body is dense task-routing tables with no background-concept padding, assuming Claude's competence throughout. Minor over-explanation could be trimmed: the "load references before starting work" instruction is repeated in the intro, the implementation-guidance section, and the numbered list, and asides like "A link or filename in this skill isn't a substitute for reading its contents" add little. Efficient but not perfectly lean, matching anchor 4 rather than 5.

Actionability

Every common task — Dashboard UI, script extensions, custom actions via script or remote function, self-hosted backends, secret storage, authentication, webhooks, onboarding, publishing, feedback — routes to a specific bundled reference file or a concrete documentation URL (e.g., "<references/script-extensions.md> and [build a custom action with a script](...)"). Per the rubric's instruction-only note, the absence of code is not penalized when guidance is this concrete and executable.

Workflow Clarity

"Load bundled reference files" gives a clear 3-step sequence (select and open references → follow pointers to other bundled references → read canonical docs) with checkpoints such as "If an example in a reference disagrees, check the version and follow the applicable canonical documentation" and "state what is unknown or unsupported before proceeding." It is below anchor 5 because build/test validation steps are delegated to references/workflow.md rather than sequenced inline, leaving minor validation gaps.

Progressive Disclosure

SKILL.md is a lean ~66-line overview while all 12 detailed reference files (~1357 lines) are split out and clearly signaled through task tables; every referenced path (discovery.md, ui-extensions.md, script-extensions.md, backend.md, authentication.md, webhooks.md, canonical-docs.md, workflow.md, onboarding-ux.md, publishing.md, feedback.md, extension-types.md) exists in the bundle. References are one level deep — the only cross-pointers (backend→webhooks, workflow→feedback) are sibling-level and the body explicitly instructs how to resolve them, matching the top anchor.

Specificity

Names several concrete actions ("Build, modify, or review Stripe Apps and extensions") and specific artifacts (stripe-app.yaml, @stripe/ui-extension-sdk, @stripe/extensibility-sdk, script extensions, custom workflow actions), but action coverage has minor gaps (testing, publishing, and debugging are not named as actions). It is above anchor 3 because far more than 1-2 concrete actions are listed, but below anchor 5's comprehensive action coverage.

Completeness

Explicitly answers both: "what" via "Build, modify, or review Stripe Apps and extensions" and "when" via the concrete trigger clauses "Use for custom Stripe Dashboard UI, stripe-app.yaml, ..." and "Also use when deciding whether a Stripe extension can support the user's billing or workflow requirements." This matches the top anchor exactly; it is not 4 because the "when" guidance is explicit rather than vague.

Trigger Term Quality

Good keyword coverage including natural phrases users would say ("custom Stripe Dashboard UI", "custom workflow actions", "billing or workflow requirements") plus distinctive technical tokens (stripe-app.yaml, SDK package names). A few natural terms a user might say — such as publishing, testing, or debugging a Stripe app — are missing, keeping it below anchor 5's comprehensive synonym coverage.

Distinctiveness Conflict Risk

Highly distinctive triggers (stripe-app.yaml, @stripe/ui-extension-sdk, @stripe/extensibility-sdk) establish a clear Stripe Apps niche, but "apps that authenticate to Stripe or react to events" and "billing ... requirements" create minor overlap risk with a generic Stripe API/billing integration skill. Mostly distinct with minor overlap, matching anchor 4 rather than 5.