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.
93
92%
Does it follow best practices?
Impact
93%
1.08xAverage score across 6 eval scenarios
Passed
No known issues
Quality
Discovery
100%Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.
This is an excellent skill description that clearly articulates specific capabilities, provides comprehensive trigger terms covering the Swift/Apple ecosystem, and explicitly states both what the skill does and when to invoke it. The description is well-structured with a capabilities section followed by clear 'Use when' and 'Invoke for' clauses, making it easy for Claude to select appropriately.
| Dimension | Reasoning | Score |
|---|---|---|
Specificity | Lists multiple specific concrete actions: 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. | 3 / 3 |
Completeness | Clearly answers both 'what' (builds apps, implements SwiftUI views, designs architectures, handles concurrency, debugs issues) and 'when' with explicit trigger guidance ('Use when building iOS/macOS applications with Swift 5.9+...' and 'Invoke for protocol-oriented programming, SwiftUI state management...'). | 3 / 3 |
Trigger Term Quality | Excellent coverage of natural terms users would say: iOS, macOS, SwiftUI, Swift 5.9+, async/await, protocol-oriented programming, actors, UIKit, Combine, Vapor, server-side Swift, watchOS, tvOS. These are all terms developers would naturally use when seeking help with Swift development. | 3 / 3 |
Distinctiveness Conflict Risk | Highly distinctive with a clear niche in Swift/Apple platform development. The specific mentions of SwiftUI, actors, Combine, Vapor, and UIKit make it very unlikely to conflict with other programming language or general development skills. | 3 / 3 |
Total | 12 / 12 Passed |
Implementation
85%Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.
This is a well-structured Swift skill with excellent actionability through concrete code examples and good progressive disclosure via the reference table. The workflow includes proper validation checkpoints with specific commands. The main weakness is moderate verbosity in the constraints section, which lists many standard Swift best practices that Claude already knows, consuming tokens without adding unique value.
Suggestions
Trim the MUST DO/MUST NOT DO constraints to only project-specific or non-obvious rules — remove items like 'don't create retain cycles' and 'use value types by default' that Claude already knows as standard Swift practice.
Consider removing the Output Templates section or making it more specific with an actual example output, as the current list is generic enough that Claude would produce similar output without it.
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The skill is reasonably efficient but includes some content Claude already knows well (e.g., Swift API Design Guidelines, basic advice like 'use value types by default', 'don't create retain cycles'). The MUST/MUST NOT lists contain several items that are standard Swift best practices Claude wouldn't need reminding of. The code examples earn their place, but the constraints section could be significantly tightened. | 2 / 3 |
Actionability | The skill provides fully executable, copy-paste-ready Swift code examples with clear ✅/❌ patterns for async/await, SwiftUI state management, protocol-oriented design, and actors. Each pattern is concrete and demonstrates both correct and incorrect approaches with specific, compilable code. | 3 / 3 |
Workflow Clarity | The core workflow has a clear 5-step sequence with an explicit validation checkpoint block specifying exact commands (`swift build`, `swift build -warnings-as-errors`, `swift test`) and when to run them. The feedback loop between steps is well-defined. | 3 / 3 |
Progressive Disclosure | The reference table cleanly signals five one-level-deep reference files with clear 'Load When' conditions, keeping the main skill as an overview. Content is well-split between inline essentials (code patterns, constraints) and detailed guidance in separate reference files. | 3 / 3 |
Total | 11 / 12 Passed |
Validation
90%Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.
Validation — 10 / 11 Passed
Validation for skill structure
| Criteria | Description | Result |
|---|---|---|
metadata_field | 'metadata' should map string keys to string values | Warning |
Total | 10 / 11 Passed | |
- Repository
- jeffallan/claude-skills
- Commit
3d95bb1
- Reviewed
Table of Contents
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