Conciseness

Mostly efficient, but the opening definition ("Dependency injection (DI) means passing dependencies to a component rather than having it create or find them") and the six-row "Why Dependency Injection?" table re-explain concepts Claude already knows, and the Best Practices Summary duplicates content that reappears in Common Mistakes (globals, init(), container-passing). Matches anchor 3 (some unnecessary explanation, could be tightened); more than the 'minor instances' of anchor 4, far leaner than the padded verbosity of anchor 2.

Actionability

Concrete, idiomatic Go code throughout — good/bad manual DI constructors, the manual-vs-container wiring comparison, a complete mock-based test, and a samber/do clone-and-override test — plus a decisive library decision table. Anchor 4 fits: guidance is mostly executable with minor gaps (e.g. the do-test example never provides a Mailer so MustInvoke[*UserService] would fail, and snippets reference undefined types like NewAPI/UserStore). Not 5 because a few examples are not fully copy-paste runnable as written.

Workflow Clarity

Both modes give a clear sequence (Design: assess → recommend → generate; Refactor: 3 parallel sub-agents → consolidate → migration plan), but neither includes any validation checkpoint — no 'run go build/vet/tests' gate after generating wiring code or refactoring a coupled codebase, and the refactoring workflow is a batch operation across many files. Per the rubric's cap, missing validation in batch operations caps this at 3, which also matches anchor 3 (sequence present, checkpoints missing or implicit) rather than anchor 4's 'most checkpoints present'.

Progressive Disclosure

Good structure: well-organized sections, and per-library wiring examples plus the full manual-DI application are correctly split into four real, clearly-signaled reference files (all exist in references/ and are one level deep, verified). Not 5 because the body is ~240 lines with substantial inline material that belongs in references — the two testing sections (~60 lines) and the decision table could be offloaded — leaving SKILL.md heavier than an overview.

Specificity

Lists several specific concrete items — "manual constructor injection, and DI library comparison (google/wire, uber-go/dig, uber-go/fx, samber/do)" and enumerated concerns ("testability, loose coupling, separation of concerns, lifecycle management") — but frames them as topics covered ("Covers why DI matters...") rather than actions, and the opener "Comprehensive guide" is mild fluff. Anchor 4 (several specific actions, minor gaps) fits better than 5, whose exemplars are direct action verbs; it is clearly above anchor 3's '1-2 concrete actions'.

Completeness

Explicitly answers both: what ("Covers why DI matters... manual constructor injection, and DI library comparison") and when ("Use this skill when designing service architecture, setting up dependency injection, refactoring tightly coupled code... or when the user asks about inversion of control, service containers, or wiring dependencies in Go"), plus routing to library-specific skills. Matches anchor 5's exemplar structure exactly; not 4, since the 'when' clause is already explicit and trigger-phrase-rich rather than needing more specificity.

Trigger Term Quality

Comprehensive natural-term coverage with synonyms: "dependency injection", "DI", "Golang"/"Go", "inversion of control", "service containers", "wiring dependencies", "singletons", "service factories", plus all four library names users would actually name. Matches anchor 5 (comprehensive natural terms including synonyms); no common phrasing is missing.

Distinctiveness Conflict Risk

Clear niche (DI in Go) with mostly distinct triggers, but a query about a specific library (e.g. uber-go/fx) could plausibly trigger both this skill and its four library-specific siblings — real overlap with closely related skills, matching anchor 4. The explicit routing sentence ("For a specific DI library, → See...") reduces the risk, but not to anchor 5's minimal-conflict level given the sibling skills share the library names in this description.