The skill is reasonably efficient but includes some unnecessary explanatory text that Claude already knows (e.g., explaining what STRIDE stands for, explaining why MD5 is bad, explaining what defense in depth means). The tables and quick reference are efficient, but the 'Security Thinking Model' and 'Research Before Reporting' sections could be tighter. The 'Why It Fails' column in anti-patterns sometimes over-explains obvious concepts.

The skill provides concrete tool commands (gosec, govulncheck, race detector) and a useful quick reference table with standard library solutions, but lacks executable code examples for the most critical patterns (e.g., no actual Go code showing parameterized SQL queries, no code showing proper exec.Command usage, no crypto/rand token generation example). The detailed code is deferred to reference files which are not provided in the bundle.

The three modes (Review, Audit, Coding) are clearly defined with distinct workflows. The audit mode specifies parallel sub-agents with explicit domains. The 'Research Before Reporting' section provides a clear 4-step investigation workflow with severity adjustment guidance. The review checklist and severity levels provide clear decision frameworks. For a skill that primarily guides security thinking and review processes rather than destructive operations, the validation checkpoints (trace data flow, check upstream validation, document decisions) are appropriate.

Excellent structure with a clear overview, quick reference table, and well-signaled one-level-deep references to 11 detailed topic files (cryptography, injection, filesystem, etc.). The main file serves as a navigational hub with enough context to act on common cases while pointing to detailed guides for deep dives. Cross-references to related skills are also included.

Lists multiple specific concrete actions and domains: injection types (SQL, command, XSS), cryptography, filesystem safety, network security, cookies, secrets management, memory safety, logging, and security tools configuration.

Clearly answers both what ('Security best practices and vulnerability prevention for Golang. Covers injection, cryptography...') and when ('Apply when writing, reviewing, or auditing Go code for security, or when working on any risky code involving crypto, I/O, secrets management, user input handling, or authentication').

Includes strong natural keywords users would say: 'SQL', 'XSS', 'crypto', 'secrets management', 'authentication', 'user input handling', 'Go code', 'security', 'vulnerability', 'auditing'. Good coverage of terms across security domains.

Clearly scoped to Golang security specifically, with distinct trigger terms like 'Go code', 'Golang', combined with security-specific vocabulary. Unlikely to conflict with general Go skills or general security skills for other languages.