Conciseness

The body is code-heavy and free of prose padding, but much of it explains SwiftUI fundamentals Claude already knows (basic VStack/HStack alignment, standard TabView setup, semantic fonts). It could be tightened to focus on HIG-specific values and conventions. Not 2 because there is no multi-paragraph conceptual filler or library-comparison padding.

Actionability

Complete, compilable SwiftUI snippets throughout (NavigationStack with NavigationPath, Tab API, symbol effects, materials, and a fully self-contained Quick Start FeatureCard). Not 5 because several examples depend on undefined symbols (items, ItemCard(item), volume, notificationCount), which are minor gaps.

Workflow Clarity

Well organized for a reference-style skill: a 'When to Use This Skill' section, a Quick Start component, Best Practices, and Common Issues give a usable orientation. Not 5 because there is no design/build sequence and no validation checkpoint (e.g., how to verify a layout against HIG or preview it), which leaves the working process implicit.

Progressive Disclosure

The bundle contains three reference files (references/hig-patterns.md, references/ios-navigation.md, references/swiftui-components.md), but the body contains zero pointers to any of them while inlining duplicate material (the Navigation Patterns section overlaps ios-navigation.md). Scored against the actual bundle structure, the references are invisible rather than merely weakly signaled. Not 3 because that anchor requires references to be 'present but not clearly signaled', whereas here no navigation exists at all and content that already lives in separate files is duplicated inline.

Specificity

Concrete actions are present ('designing iOS interfaces', 'implementing SwiftUI views', 'building native iOS apps') but the lead phrase 'Master iOS Human Interface Guidelines and SwiftUI patterns' is a generic pattern rather than a concrete action, leaving minor gaps in coverage. Not 5 because 'Master X' is padding and the action list is not comprehensive of the domain.

Completeness

Explicitly answers both: the 'what' ('Master iOS Human Interface Guidelines and SwiftUI patterns for building native iOS apps') and the 'when' ('Use when designing iOS interfaces, implementing SwiftUI views, or ensuring apps follow Apple's design principles') with three concrete trigger phrases. Clearly matches the anchor-5 example shape.

Trigger Term Quality

Good natural keyword coverage: 'iOS', 'SwiftUI', 'Apple's design principles', 'native iOS apps' are terms users would actually say. Not 5 because common synonyms like 'iPhone', 'iPad', 'HIG', 'UIKit', or 'Xcode' are missing.

Distinctiveness Conflict Risk

A clear Apple-platform niche with distinct triggers (SwiftUI, HIG, Apple's design principles); minimal conflict risk since these terms would not naturally fire a non-Apple design skill. Not 4 because no specific overlapping sibling skill's territory is plausibly claimed.