Code Review Skill

Provide thorough, multi-agent code review for pull requests with high-confidence issue detection.

When to Use

• Reviewing a pull request before merge.
• Checking code changes for bugs and AGENTS.md/CLAUDE.md compliance.
• Validating that changes align with historical context and existing code comments.

Agent Compatibility

This skill is tool-agnostic and can be executed by Claude Code, OpenAI Codex CLI, GitHub Copilot CLI, or Gemini CLI. When posting the PR comment, replace <agent-name> in the output template with the active agent name.

Inputs

• Pull request URL or number (required).
• Repository context with AGENTS.md/CLAUDE.md files.

If the pull request is not specified, ask for it before proceeding.

Workflow

1. Eligibility Check (fast agent): Verify the PR is eligible for review:

   • Not closed
   • Not a draft
   • Not automated or trivially simple
   • No prior code review from this tool

2. Gather AGENTS.md/CLAUDE.md Files (fast agent): Collect paths to relevant guideline files:

   • Root AGENTS.md or CLAUDE.md (if exists)
   • AGENTS.md/CLAUDE.md files in directories modified by the PR

3. Summarize Changes (fast agent): View the PR and return a summary of the change.

4. Parallel Code Review (5 default agents): Each agent reviews independently and returns issues with reasons:

   • Agent 1: Audit changes for AGENTS.md/CLAUDE.md compliance
   • Agent 2: Shallow scan for obvious bugs (focus on large issues, avoid nitpicks)
   • Agent 3: Review git blame and history for context-aware bug detection
   • Agent 4: Check previous PRs touching these files for relevant comments
   • Agent 5: Verify changes comply with guidance in code comments

5. Score Issues (fast agents, parallel): For each issue found, score confidence (0-100):

   • 0: False positive, doesn't stand up to scrutiny
   • 25: Might be real, couldn't verify, stylistic without AGENTS.md/CLAUDE.md backing
   • 50: Verified real but may be a nitpick or rare
   • 75: Double-checked, very likely real, important impact or AGENTS.md/CLAUDE.md-mentioned
   • 100: Absolutely certain, will happen frequently, evidence confirms

6. Filter Issues: Keep only issues with score >= 80.

7. Re-check Eligibility (fast agent): Confirm PR is still eligible for review.

8. Post Comment: Use gh pr comment to post results to the PR.

False Positive Guidelines

Exclude these from reported issues:

• Pre-existing issues (not introduced by the PR)
• Apparent bugs that aren't actually bugs
• Pedantic nitpicks a senior engineer wouldn't flag
• Issues caught by linters, typecheckers, or compilers
• General code quality issues unless required in AGENTS.md/CLAUDE.md
• AGENTS.md/CLAUDE.md issues explicitly silenced in code
• Intentional functionality changes related to the broader change
• Real issues on lines not modified by the PR

Output Format

When Issues Found

### Code review

Found N issues:

1. <brief description> (AGENTS.md/CLAUDE.md says "<relevant quote>")

<link to file and line with full sha1 + line range>

2. <brief description> (some/other/AGENTS.md says "<...>")

<link to file and line with full sha1 + line range>

Generated with <agent-name>

<sub>- If this code review was useful, please react with thumbs up. Otherwise, react with thumbs down.</sub>

When No Issues Found

### Code review

No issues found. Checked for bugs and AGENTS.md/CLAUDE.md compliance.

Generated with <agent-name>

Link Format Requirements

When linking to code:

• Use full git SHA (not $(git rev-parse HEAD))
• Format: https://github.com/owner/repo/blob/<full-sha>/path/file.ext#L<start>-L<end>
• Include at least 1 line of context before and after
• Repo name must match the PR's repository

Constraints

• Do not run builds, typechecks, or tests (CI handles these).
• Use gh CLI for all GitHub interactions.
• Create a todo list before starting.
• Cite and link every reported issue.
• Keep output brief, avoid emojis in comments.

Outputs

• Comment posted to the pull request with review results.