Conciseness

The body is a dense, rule-oriented summary with almost no explanation of concepts Claude already knows, fitting anchor 4 (efficient with minor trimmable instances). The 5 sub-agent categories are listed three times ("Fan out the five category sub-agents", the Audit-mode bullet, and the 'Parallelizing Error Handling Audits' section), and the intro sentence "This skill guides the creation of robust, idiomatic error handling in Go applications" is pure filler — but the padding is minor, not the 'several unnecessary explanations' of anchor 2.

Actionability

Guidance is concrete and executable in form: exact patterns like "fmt.Errorf(\"{context}: %w\", err)", "errors.AsType[T](err)", "errors.Join", and unambiguous MUST/SHOULD rules ("Error strings MUST be lowercase, without trailing punctuation"). It falls short of anchor 5 only because no copy-paste code examples appear in SKILL.md itself — the code detail is delegated to reference files, which is a defensible split.

Workflow Clarity

The three modes (Coding, Review, Audit) are clearly delineated with explicit sequencing and parallelism guidance, but validation checkpoints are entirely absent — nothing says to verify with `go build`, `go test`, or `golangci-lint` even though both tools are listed in allowed-tools. Per the anchor definitions, a present sequence with missing/implicit checkpoints is a 3, not 4.

Progressive Disclosure

The body is a clean overview: a 15-point best-practices summary, a 'Detailed Reference' section where each of the three bundle files (error-creation.md, error-wrapping.md, error-handling.md — all present in ./references/) is linked with a description of its contents, one level deep with no nesting. This matches the anchor-5 pattern of a clear overview with well-signaled one-level-deep references.

Specificity

The description enumerates many concrete, specific capabilities: "creation, wrapping with %w, errors.Is/As, errors.Join, custom error types, sentinel errors, panic/recover, the single handling rule, structured logging with slog, HTTP request logging middleware, and samber/oops" — comprehensive coverage with no vague fluff, matching the anchor-5 example's breadth. It is written in third person ("Idiomatic Golang error handling"), so no voice penalty applies.

Completeness

It clearly answers 'what' (the full enumerated capability list) and 'when' with an explicit trigger clause: "Apply when creating, wrapping, inspecting, or logging errors in Go code." This mirrors the anchor-5 good example structure of what followed by an explicit Use-when statement.

Trigger Term Quality

Natural terms a user would actually say are comprehensively covered: "error handling", "Golang" and "Go code" (both variants), "wrapping", "logging errors", plus specific API keywords users mention directly (%w, errors.Is/As, errors.Join, panic/recover, slog). This matches the anchor-5 pattern of including synonyms and variations.

Distinctiveness Conflict Risk

The niche is clear (Go error handling) and it proactively delegates overlapping scope ("For samber/oops specifics → See `samber/cc-skills-golang@golang-samber-oops` skill"), which reduces conflict. However, "logging errors in Go code" still overlaps noticeably with the sibling observability/slog skills, so it is not fully anchor-5 minimal-conflict; it sits above the anchor-3 'could still overlap' case.