Conciseness

The body is dense and fluff-free — no concept explanations Claude already knows, and the Anti-Rationalization table is high-value non-obvious domain knowledge (e.g., 'GroupSession is not Sendable', 'deliveryMode is a let fixed at init'). The trimmable part is duplication: the same routing map appears four ways (Quick Reference table, dot graph, numbered Decision Tree, Example Invocations), with the ~30-line dot graph adding nothing over the numbered list. Efficient with minor instances that could be trimmed — anchor 4, not 5, because every token does not earn its place.

Actionability

Every routing entry gives a concrete, executable directive with an exact target path ('Siri playback in an audio app ("play X in MyApp") ... → See skills/siri-audio.md'), and triggers include literal error strings users will paste ('Missing required parameter', 'hasn\u0027t added support for that with Siri', 'I can\u0027t play that'). Example Invocations map real user utterances to specific files. For an instruction-only routing skill this is copy-paste-ready guidance covering the common cases — anchor 5.

Workflow Clarity

The skill's single action — route to the right reference — is unambiguous, and it is supported by layered disambiguation: the numbered decision tree with sub-branches (1a/1b/1c), Cross-Domain Routing for tasks spanning multiple skills, and an explicit Conflict Resolution section that tie-breaks overlaps with axiom-build/axiom-data/axiom-media (the routing equivalent of validation checkpoints). No destructive or batch operations exist, so the validation cap does not apply; the routing decision process could not be much clearer.

Progressive Disclosure

The SKILL.md is a pure overview/router: all implementation detail lives in clearly signaled, one-level-deep references ('See skills/extensions-widgets.md', 'See skills/storekit-ref.md') organized into a scannable symptom table — exactly the anchor-5 pattern. Each Anti-Rationalization row that carries inline API detail ends by pointing to its reference file, keeping the overview an overview. Note: no bundle files were provided in this review copy, so the skills/*.md targets could not be verified against actual file listings; the score reflects the structure as written.

Specificity

The description enumerates many concrete, named surfaces ("Siri and Shortcuts, widgets, Live Activities, in-app purchase, localization, privacy prompts, alarms, timers, calendar, reminders, contacts, SharePlay, VoIP and CallKit, accessory pairing, weather, Spotlight indexing, background tasks, Background Assets, push") with no vague filler, but it names domains rather than actions — no verb ever states what the skill does with them. Above the anchor-3 example (1-2 concrete actions) on coverage and concreteness, below anchor 5, which requires specific actions; the implicit action 'integrate with' is never made explicit.

Completeness

The 'when' is explicit and exemplary ("Use when work crosses into Apple's system surfaces rather than your own UI or data — ..."), but the 'what' is only implied by the domain list; the description never states what the skill actually does (provide implementation guidance? route to references? audit?). It is richer than anchor 2 ('only when present without what') because the enumeration conveys the domain, but it lacks the explicit action statement required by anchors 4 and 5, and the guideline says to score only what is explicitly stated.

Trigger Term Quality

Excellent natural terms users would actually say: "Siri and Shortcuts", "widgets", "Live Activities", "in-app purchase", "alarms", "timers", "calendar", "reminders", "contacts", "SharePlay", "VoIP", "weather", "push". A few common variations are missing — "App Intents" (a major routing topic in the body), "notifications", "Dynamic Island", "StoreKit" — so it fits anchor 4 ('good keyword coverage; a few natural terms missing') rather than the comprehensive synonym coverage of anchor 5.

Distinctiveness Conflict Risk

The boundary clause "rather than your own UI or data" explicitly separates this skill from sibling UI/data skills, and every enumerated trigger (CallKit, Background Assets, SharePlay, accessory pairing) is a distinct iOS-system-surface niche. Apple Pay and camera/audio — routed to sibling skills in the body — are correctly absent from the trigger list, minimizing wrong-skill triggering. Clear niche with distinct triggers, matching anchor 5.