Conciseness

The body is mostly lean — the Fiber-specific gotchas ("Fiber uses fasthttp under the hood, not net/http", "Ctx is pooled and reused", "Use c.UserContext() instead of c.Context()") are exactly what Claude does not already know. However, the "Common Commands" section re-teaches basic Go commands ("go test ./... -v -race", "gofmt -w .", "go mod tidy") Claude already knows, and the ~500-line monolith of full application code could be tightened.

Actionability

The scaffold command with exact `go get` lines, project tree, and complete copy-paste-ready Go files (main, router, handlers, auth middleware, DB connect) cover the common cases well. Minor gaps keep it from 5: `github.com/golang-jwt/jwt/v5` is imported but missing from the `go get` list, `config.Load()` is used but `config.go` is never shown, `.env.example` is referenced without contents, and the First Steps reference a `migrations` directory absent from the project structure.

Workflow Clarity

The overall flow is coherent (prerequisites → scaffold → structure → conventions → patterns → First Steps) and "First Steps After Scaffold" ends with an explicit verification ("curl http://localhost:8080/healthz"). It misses 5 because there are no validation checkpoints after the migration step and no error-recovery guidance (e.g., what to do if `migrate` fails or the DB is unreachable).

Progressive Disclosure

Sections are clearly headed and logically ordered, but the skill is a ~500-line monolith with zero reference files: full application code (complete handler CRUD file, router, SQLX alternative, websocket/v3 integration notes) is inlined in SKILL.md when it clearly belongs in `references/` files one level deep.

Specificity

The description names several concrete capability areas — "Scaffold and develop high-performance REST APIs", "Fiber v2 web framework", "GORM/SQLX", "Express-inspired routing" — which goes beyond naming just the domain. It falls short of a 5 because the action verbs are only "scaffold" and "develop", giving minor gaps in coverage of what the skill actually does.

Completeness

The "what" is clearly stated (scaffolding and developing REST APIs with Fiber v2, GORM/SQLX), but there is no "Use when..." clause or any equivalent explicit trigger guidance, capping completeness at 3 per the judging guidelines. The "when" is entirely absent rather than weakly implied, so it cannot score 4.

Trigger Term Quality

It includes natural terms users would say when needing this skill: "Fiber", "REST APIs", "Go", "GORM", "SQLX", "Express". A few natural variations are missing, such as "golang", "backend", "web server", or "API server", which prevents a 5.

Distinctiveness Conflict Risk

Naming the specific framework "Fiber v2" alongside "GORM/SQLX" carves out a clear niche with minimal conflict risk against generic skills. There is minor overlap risk with other Go web-framework skills (e.g., Gin or Echo starters), which keeps it below 5.