code-reviewer

A general code-review guide for checking source code or a change before it is merged. It covers whether the code works, is understandable, maintainable, reasonably efficient, and consistent with the project.

In plain words
What is it for?
Use it to review a pull request, file, function, or code change when no narrower review focus—such as security or performance—was requested.
Why use it?
It helps find logic mistakes, missed edge cases, unnecessary work, and design problems before they reach the main codebase.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/codebygarv/ai-skills/code-reviewer
Any agent
npx skills add codebygarv/Ai-skills --skill code-reviewer
Clone the repo
git clone --depth 1 https://github.com/codebygarv/Ai-skills

Made for: Claude Code, Codex.

Per session 46 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 488 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00046 $0.00488
Opus 5 $0.00023 $0.00244
Sonnet 5 $0.00009 $0.00098
Haiku 4.5 $0.00005 $0.00049

Measured 2d ago against content hash 774a2064362e, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

code-reviewer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/development/code-reviewer/SKILL.md · 35 lines

How it starts

The opening of the file, as written. The whole thing — 35 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Purpose

Provide a thorough, general-purpose code review covering correctness, readability, maintainability, and performance — the kind of review a careful senior engineer would leave on a diff.

When to Use

  • Reviewing a diff, PR, file, or function before merge.
  • The user asks for "a code review" without narrowing to a specific concern (security, types, performance) — those narrower concerns have their own skills (Security Auditor, TypeScript Guardian, Performance Auditor) and this skill should defer to them for deep dives in those areas while still flagging obvious issues.

What to Analyze

  1. Correctness — logic errors, off-by-ones, incorrect assumptions about inputs, unhandled null/undefined/empty cases.
  2. Readability — naming, function length, nesting depth, whether intent is obvious without extra explanation.
  3. Maintainability — duplication, tight coupling, magic numbers/strings, missing abstraction where a pattern repeats 3+ times.
  4. Performance — obviously wasteful operations (N+1 queries, unnecessary re-computation, quadratic loops over data that can grow).
  5. Consistency — does it match the surrounding codebase's existing patterns and conventions.
  6. Error handling — are failure paths handled, or silently swallowed/ignored.

Output Format

  • Group findings by severity: Blocking (bugs, correctness issues) → Should Fix (maintainability, missing error handling) → Nit (style, naming).
  • Each finding: file/line reference, what's wrong, and a concrete suggested fix — not just "this could be better."
  • End with what's done well, briefly — but only if genuinely true, not as a formality.

Avoid

  • Rewriting the whole file as "feedback" instead of pointing at specific issues.
  • Nitpicking style that a linter/formatter already enforces.
  • Flagging a pattern as wrong when it's actually the codebase's established convention — check for consistency first.

Read the full file on GitHub · 35 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 35 lines · 46 tokens per session scan A 774a2064362e

Subscribe to this mod's changes

code-reviewer is a skill published in the GitHub repository codebygarv/Ai-skills (24 stars, last pushed 13d ago), licensed MIT. It adds 46 tokens to every session and 488 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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