Conciseness

The bulk is efficient — code examples carry the content and no basic Swift or DI concepts are re-explained — but the 'When to Activate' and 'When to Use' sections are near-duplicate bullet lists and the opening sentence restates the frontmatter description. This redundancy is a whole trimmable section rather than minor over-explanation, fitting anchor 3 rather than 4.

Actionability

Every pattern step is backed by concrete, realistic Swift code (protocols, default implementations, mocks, default-parameter injection, Swift Testing tests). Minor gaps keep it from anchor 5: the test examples use `MockFileSystemProvider` and `manager.loadData()`, neither of which is defined in the shown code.

Workflow Clarity

The Core Pattern is a clearly sequenced five-step workflow (define protocols → default implementations → mocks → inject with default parameters → write tests), each step with executable code, and it involves no destructive or batch operations so the validation cap does not apply. It lacks the explicit verification checkpoints or checklist of anchor 5, and the test snippets' undefined references slightly muddy the follow-along path.

Progressive Disclosure

The single-file body is well organized into scannable sections (When to Activate, Core Pattern steps 1–5, Best Practices, Anti-Patterns) with no nested or buried references, and no bundle files exist to misstructure. It stays at anchor 4 rather than 5 because the ~185-line body keeps everything inline — the extended default-implementation and test examples could be split into reference files — and the skill exceeds the under-50-line simple-skill exception.

Specificity

The description lists several concrete capabilities — 'mock file system, network, and external APIs using focused protocols and Swift Testing' — anchored in a specific technique ('Protocol-based dependency injection for testable Swift code'). It falls short of anchor 5 because coverage is not comprehensive (network and external API mocking are named but not elaborated), but exceeds anchor 3 since multiple distinct actions are named.

Completeness

The 'what' is clearly stated (protocol-based DI for mocking external dependencies in Swift), but there is no 'Use when...' clause or equivalent explicit trigger guidance anywhere in the description, which caps completeness at 3 per the judging guidelines. This matches anchor 3 exactly: clear what, missing when.

Trigger Term Quality

It includes the natural terms a Swift developer would actually say — 'dependency injection', 'mock', 'testable', 'protocol', 'Swift Testing' — giving good keyword coverage. It misses common variations and synonyms like 'unit test', 'XCTest', 'test double', or 'stub', keeping it below anchor 5.

Distinctiveness Conflict Risk

The Swift-specific framing ('Protocol-based dependency injection... Swift code... Swift Testing') carves out a mostly distinct niche with minor overlap risk against general testing or mocking skills. It does not reach anchor 5 because no explicit trigger phrases sharpen the distinction further.