Conciseness

The ~64-line body is a lean router: task tables with exact file paths and URLs, plus purposeful guardrails ("Don't infer support from an extension's name or the existence of a scaffold", "A full-stack app doesn't require every document in the skill"). No concept explanations Claude already knows and no padding, matching anchor 5's "every token earns its place".

Actionability

For an instruction-only routing skill, guidance is fully executable: each task maps to exact bundled paths (e.g., "<references/script-extensions.md> and [build a custom action with a script](...)") and canonical URLs, with concrete path-resolution rules ("Resolve `references/` paths relative to this skill's directory") and tool directives ("Prefer `stripe docs` when available"). Specific coverage of common cases matches anchor 5; anchor 4's "minor gaps" is not evidenced.

Workflow Clarity

Clear sequenced workflow (select capability via product docs → load implementation guides → shared lifecycle references → numbered 3-step loading procedure) with a doc-conflict feedback loop ("If an example in a reference disagrees, check the version and follow the applicable canonical documentation") and a pre-proceeding checkpoint ("state what is unknown or unsupported before proceeding"). Not 5 because runtime validation and testing steps are delegated to the referenced guides rather than enumerated with explicit checkpoints in this file, leaving minor validation gaps per anchor 4.

Progressive Disclosure

Verified against the actual bundle: SKILL.md is a pure overview router, all 12 referenced files (references/*.md) exist with substantive content (35–211 lines each), references are clearly signaled in task tables, and inter-bundle cross-references are only one level deep (workflow.md → feedback.md, backend.md → webhooks.md) with explicit navigation rules. This matches anchor 5's clear overview with well-signaled one-level-deep references; the deep-nesting penalty of anchor 1 does not apply.

Specificity

Lists several concrete actions ("Build, modify, or review Stripe Apps and extensions", "deciding whether a Stripe extension can support the user's billing or workflow requirements") alongside concrete objects (stripe-app.yaml, SDK packages). Not 5 because task verbs like testing, debugging, and publishing are not named; clearly above anchor 3, which expects only 1-2 concrete actions.

Completeness

Explicitly answers both questions: "what" via "Build, modify, or review Stripe Apps and extensions using the relevant documentation and reference guides" and "when" via "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 anchor 5's requirement of concrete trigger phrases for both; anchor 4's weaker 'when' does not apply.

Trigger Term Quality

Comprehensive natural terms with synonyms and exact identifiers users would say: "Stripe Apps", "extensions", "custom Stripe Dashboard UI", "script extensions", "custom workflow actions", plus the manifest filename "stripe-app.yaml" and both package names "@stripe/ui-extension-sdk" and "@stripe/extensibility-sdk" — matching anchor 5's coverage including file-extension-equivalent identifiers. Not below 5 since no common variation is materially missing.

Distinctiveness Conflict Risk

Clear niche (Stripe Apps/extensions) with distinct triggers including unique package names and the stripe-app.yaml manifest, so minimal conflict risk with other skills — matching anchor 5. Anchor 4's "minor overlap risk with closely related skills" would require some ambiguity with sibling skills, which the specific identifiers preclude.