Gemini Reviewer Skill

IMPORTANT: This skill executes automatically. When invoked, follow these steps precisely.

Execution Protocol

When this skill is invoked, you MUST:

1. Identify the review target from conversation context:

   • Look for PR/MR numbers mentioned
   • Look for commit hashes mentioned
   • Look for code snippets or implementation plans
   • Check recent tool calls (glab mr view, gh pr view, git diff, etc.)

2. Prepare comprehensive review context file:

   • Include MR/PR title and description
   • Include all code changes (diff)
   • Include relevant file contents
   • Include upstream issues or comments
   • Include helper functions or related code

3. Execute Gemini review using Bash tool with read-only security:

   gemini --approval-mode plan -o text -p "You are an expert code reviewer. Review this [MR/PR/code] and provide detailed feedback on correctness, security, performance, code quality, and testing. Be specific and reference line numbers or code sections." < /tmp/gemini_context.txt
   

   SECURITY NOTE:

   • --approval-mode plan: Read-only mode preventing all tool execution
   • Gemini can only analyze the provided context and return text feedback
   • No file system modifications, git operations, or shell commands possible
   • Note: Docker --sandbox not used due to enterprise UID compatibility issues

4. Return the complete Gemini output - do not summarize or filter

Context File Template

Create /tmp/gemini_context.txt with this structure:

Review [GitLab MR/GitHub PR/Commit] #[NUMBER]: "[TITLE]"

## CONTEXT

**Purpose:** [What this change does]

**Related Issues:** [Links to upstream issues, bugs, etc.]

**Rationale:** [Why this change is needed]

**CI Status:** [Pipeline/test results if available]

## CHANGES SUMMARY

[High-level summary of what files changed and why]

## DETAILED CODE CHANGES

### File: [filename]
```[language]
[Show diff with - and + for removed/added lines]

File: [filename2]

[Show diff]

HELPER FUNCTION CONTEXT

[Include any related helper functions or dependencies that aren't in the diff]

REVIEW FOCUS

Please review focusing on:

1. Correctness: Logic errors, edge cases
2. Security: Input validation, vulnerabilities
3. Performance: Scalability, efficiency concerns
4. Edge Cases: Null handling, error conditions
5. Architecture: Design soundness, alternatives
6. Code Quality: Readability, maintainability
7. Testing: What tests should be added?
8. Configuration: Impact of config changes

Provide specific, actionable feedback with line references.

## Example Execution

**Scenario:** /code-review command called with MR 44

Following the execution protocol above, here's a concrete example:

```bash
# Step 2: Prepare context file
cat > /tmp/gemini_context.txt << 'EOF'
Review GitLab Merge Request #44: "Tuning rag score thresholds"

## CONTEXT
[Full MR description, purpose, rationale]

## DETAILED CODE CHANGES
[Complete diff from glab mr diff]

## REVIEW FOCUS
[Specific areas to examine]
EOF

# Step 3: Execute Gemini in read-only plan mode
gemini --approval-mode plan -o text -p "You are an expert code reviewer. Review this merge request and provide detailed feedback on correctness, security, performance, and code quality. Be specific and reference line numbers." < /tmp/gemini_context.txt

Critical Rules

• ALWAYS use --approval-mode plan - Read-only mode preventing all tool execution
• ALWAYS use -p flag - Required for prompts when using stdin input
• NEVER use -y/YOLO mode - Auto-approves dangerous operations (rm, git reset, etc.)
• ALWAYS use -o text - Clean text output format
• DO NOT use --sandbox - Has compatibility issues with enterprise UID ranges (4212687 > 60000)
• DO NOT summarize or filter Gemini's output - return it verbatim
• DO gather sufficient context - include diffs, descriptions, related code
• DO focus the prompt - tell Gemini what to look for
• DO use temporary files (/tmp/gemini_context.txt) for large context

Troubleshooting

If Gemini is not installed:

• Report to user that Gemini CLI is not available
• Skip Gemini review and note it in the combined output

If Gemini returns an error:

• Include the error in the output
• Note that Gemini review failed but continue with other reviews

Integration with /code-review

This skill is automatically invoked by /code-review command alongside Claude's code-reviewer agent. Both run in parallel for comprehensive coverage.