Conciseness

The body is dense with non-obvious, version-specific rules (hour limits, token rotation, APNs header values) and never explains concepts Claude already knows, but the opening paragraph restates the frontmatter description's routing text and the TOC adds lines that could be trimmed. Efficient with minor trimmable instances, matching the 4 anchor rather than the every-token-earns-its-place 5.

Actionability

Concrete, executable identifiers appear throughout — "NSSupportsLiveActivities = YES", "apns-push-type: liveactivity", "activity.pushTokenUpdates", exact hour limits — plus a compilable ActivityAttributes/ContentState struct, but the complete request/update/end call sites and payload fixtures are deferred to reference files rather than shown, leaving minor gaps versus the copy-paste-ready 5 anchor.

Workflow Clarity

The "For a new Live Activity" section gives a clearly sequenced 5-step process with embedded validation checkpoints ("encode a representative server fixture before integrating APNs", "exercise local update plus every terminal end path", "validate update, end, and push-to-start payloads against the same Codable contract") and a dedicated Review Checklist for the complex process. Not 4 because validation is explicit and checkpoints are present at each phase.

Progressive Disclosure

The SKILL.md is a genuine overview that routes by topic with labeled pointers to three real bundle files (all verified to exist: lifecycle-updates-and-push.md, ending-and-presentation.md, concurrency-state-and-testing.md), references are one level deep with no nested .md chains, and navigation is easy via the Contents and References sections — a clear match to the 5 anchor.

Specificity

"Build or review Live Activities and Dynamic Island experiences with ActivityKit, including lifecycle, layouts, push updates, and scheduled delivery" lists several specific capability areas, but the action verbs themselves are broad (build, review) rather than the multiple granular concrete actions of the 5 anchor, and minor coverage gaps exist (e.g., token handling, testing).

Completeness

Both questions are explicitly answered: the "what" is concrete ("Build or review... including lifecycle, layouts, push updates, and scheduled delivery") and the "when" uses an explicit trigger clause with concrete phrases ("Use for time-sensitive Lock Screen or Dynamic Island state"). Not 4 because the trigger guidance is specific and explicit rather than generic.

Trigger Term Quality

Natural iOS terms users would actually say are present — "Live Activities", "Dynamic Island", "Lock Screen", "push updates", "ActivityKit" — but a few common variants are missing (e.g., singular "Live Activity", "push-to-start", "widget extension"), so it falls just short of the comprehensive-synonym coverage of the 5 anchor.

Distinctiveness Conflict Risk

Clear niche (ActivityKit Live Activities / Dynamic Island) with distinct triggers, and it even resolves the nearest conflict explicitly ("route ordinary widgets to widgetkit"), giving minimal overlap risk with related widget/push skills.