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swift-expert

Builds iOS/macOS/watchOS/tvOS applications, implements SwiftUI views and state management, designs protocol-oriented architectures, handles async/await concurrency, implements actors for thread safety, and debugs Swift-specific issues. Use when building iOS/macOS applications with Swift 5.9+, SwiftUI, or async/await concurrency. Invoke for protocol-oriented programming, SwiftUI state management, actors, server-side Swift, UIKit integration, Combine, or Vapor.

Quality

88%

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SKILL.md
Quality
Evals
Security

Quality

Content

78%Weight 40%Scale 1-5

Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.

A well-structured, actionable skill body with a genuinely excellent reference-table progressive-disclosure design and explicit validation commands in the workflow. The main gaps are the absence of error-recovery guidance at the validation checkpoints and minor tightening opportunities in the code examples.

Suggestions

Add feedback-loop guidance to the validation checkpoints (e.g. 'If `swift build -warnings-as-errors` fails, fix actor isolation/Sendable warnings and re-run before proceeding'), which is the missing piece for workflow_clarity to reach the top anchor.

Replace the `{ /* … */ }` placeholder bodies in the UserRepository example with complete implementations so every code pattern is copy-paste ready.

Trim the DON'T examples to brief one-line contrasts and fix the force-unwrap `URL(string:...)!` in the DO fetchUser example, which contradicts the MUST NOT rule against unjustified force unwrapping.

DimensionReasoningScore

Conciseness

The body is prescriptive rather than tutorial — it teaches preferences ("prefer actor isolation", "Avoid class inheritance for shared behavior") instead of re-explaining Swift basics, and the DO/DON'T contrast adds decision value. Not a 5 because the full DON'T code blocks (e.g. a complete UnsafeImageCache class and a LegacyViewModel just to say "prefer @Observable") could be trimmed to one-line notes, and the DO fetchUser example even embeds a force-unwrap that contradicts the MUST NOT list.

4 / 5

Actionability

Four concrete, largely executable Swift patterns plus exact validation commands (`swift build`, `swift build -warnings-as-errors`, `swift test`) give copy-paste-ready guidance for the common cases. Not a 5 because the UserRepository example uses `{ /* … */ }` placeholder bodies rather than complete implementations — exactly the 'concrete code with minor gaps' anchor-4 case; not a 3 because three of four patterns are fully executable and commands are specific.

4 / 5

Workflow Clarity

The five-step Core Workflow has explicit validation checkpoints with commands ("After step 3, run `swift build`... After step 4, run `swift build -warnings-as-errors`... After step 5, run `swift test`"), which is stronger than the anchor-4 example's vague 'verify output'. Not a 5 because anchor 5 also expects feedback loops for error recovery — there is no guidance on what to do when a checkpoint fails — so it sits between 4 and 5; this is not a destructive/batch skill so no cap applies.

4 / 5

Progressive Disclosure

The Reference Guide table maps each topic to an existing one-level-deep file (all five of references/swiftui-patterns.md, async-concurrency.md, protocol-oriented.md, memory-performance.md, testing-patterns.md are present) with an explicit "Load When" column signaling when to pull each. Not a 4 because navigation, splitting, and signaling all match the anchor-5 structure with no nested references.

5 / 5

Total

17

/

20

Passed

Description

92%Weight 40%Scale 1-5

Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.

A strong description: third-person, specific, and comprehensive on both capabilities and usage triggers. The only improvement space is adding a few more natural trigger variations such as the .swift extension or Xcode.

DimensionReasoningScore

Specificity

The description lists six concrete actions in third person — "Builds iOS/macOS/watchOS/tvOS applications, implements SwiftUI views and state management, designs protocol-oriented architectures, handles async/await concurrency, implements actors for thread safety, and debugs Swift-specific issues" — matching the comprehensive-coverage anchor. Not a 4 because the action list covers building, state management, architecture, concurrency, thread safety, and debugging with no noticeable gaps.

5 / 5

Completeness

Both questions are explicitly answered: the "what" via the action list and the "when" via "Use when building iOS/macOS applications with Swift 5.9+, SwiftUI, or async/await concurrency. Invoke for protocol-oriented programming, ... UIKit integration, Combine, or Vapor" — concrete trigger phrases matching the anchor-5 example. Not a 4 because the 'when' clauses are already explicit and specific.

5 / 5

Trigger Term Quality

Strong natural coverage — "SwiftUI", "async/await", "UIKit", "Combine", "Vapor", "actors", "server-side Swift" — but a few common terms users would say are missing, e.g. ".swift" file extension, "Xcode", or plain "Swift code". Not a 5 because the comprehensive anchor explicitly expects synonyms and file extensions; not a 3 because keyword coverage is broad and clearly natural rather than jargon-only.

4 / 5

Distinctiveness Conflict Risk

It carves out a clear niche (Apple-platform Swift development) with distinct triggers like SwiftUI, Combine, Vapor, and actors, so it is unlikely to fire for unrelated skills. Not a 4 because the only conceivable overlap is with a hypothetical general mobile-development skill, which is minor.

5 / 5

Total

19

/

20

Passed

Validation

100%

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation — 16 / 16 Passed

Validation for skill structure

No warnings or errors.

Repository

Jeffallan/claude-skills

Path

skills/swift-expert/SKILL.md

Reviewed

Table of Contents

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