Lists numerous specific concrete actions and concepts: error creation, wrapping with %w, errors.Is/As, errors.Join, custom error types, sentinel errors, panic/recover, structured logging with slog, HTTP request logging middleware, and samber/oops. This is highly specific and comprehensive.

Clearly answers 'what' (idiomatic Go error handling with specific techniques listed) and 'when' with an explicit trigger clause: 'Apply when creating, wrapping, inspecting, or logging errors in Go code.'

Includes many natural keywords a Go developer would use: 'error handling', 'wrapping', '%w', 'errors.Is', 'errors.As', 'errors.Join', 'sentinel errors', 'panic/recover', 'slog', 'Go code', 'logging errors'. These cover a wide range of terms users would naturally mention.

Highly distinctive — narrowly scoped to Go error handling specifically, with Go-specific terminology (errors.Is/As, %w, slog, samber/oops) that would not conflict with general coding skills or error handling in other languages.

The content is mostly efficient with a well-structured summary list and clear references, but includes some unnecessary verbosity — the persona section, mode descriptions, and the community default note add tokens without much actionable value. The best practices summary is tight, but the detailed reference descriptions repeat information that could be left to the referenced files.

The best practices summary provides specific, concrete rules (e.g., 'use fmt.Errorf("{context}: %w", err)'), but there are no executable code examples in the SKILL.md itself — all concrete code is deferred to reference files. The guidance is specific enough to act on but falls short of copy-paste ready without the referenced files.

The three modes (Coding, Review, Audit) provide some workflow structure, and the parallel sub-agent audit breakdown is well-organized. However, there are no explicit validation checkpoints or feedback loops — for example, the audit mode doesn't specify what to do when violations are found, and the coding mode's background sub-agent suggestion lacks concrete steps for handling discovered issues.

Excellent progressive disclosure structure: a concise overview with numbered best practices, clearly signaled one-level-deep references to three detailed files (error-creation.md, error-wrapping.md, error-handling.md), cross-references to related skills, and external library references. Navigation is clear and well-organized.