validate-changes - SKILL.md Agent Skill

name: validate-changes description: Evaluate staged changes using LLM-as-a-Judge before committing effort: medium disable-model-invocation: true

Validate Changes Before Commit

Evaluate staged git changes using the output-evaluator agent to catch issues before committing.

Process

Step 1: Check for Staged Changes

Run git diff --cached --stat to see what's staged. If nothing is staged, inform the user and exit.

Step 2: Get the Full Diff

Run git diff --cached to get the complete diff of all staged changes.

Step 3: Invoke the Evaluator

Use the Task tool to launch the output-evaluator agent with the diff:

Evaluate these staged changes for correctness, completeness, and safety.
Return a JSON verdict with scores and issues.

Changes:
[paste the git diff here]

Step 4: Parse and Act on Verdict

Based on the evaluation result:

If APPROVE:

Tell the user the changes passed evaluation
Show the summary and scores
Ask if they want to proceed with commit

If NEEDS_REVIEW:

Show all issues found (grouped by severity)
Show the suggestion from the evaluator
Ask the user how to proceed:
- Fix issues and re-evaluate
- Commit anyway (acknowledge risks)
- Abort

If REJECT:

Clearly state the changes were rejected
Show critical issues that caused rejection
Do NOT offer to commit anyway
Suggest specific fixes

Step 5: Commit (if approved)

If user confirms, create the commit using the standard commit flow.

Usage Examples

/validate-changes

Output:

Evaluating 3 staged files...

VERDICT: NEEDS_REVIEW

Scores:
  Correctness:  8/10
  Completeness: 6/10
  Safety:       9/10

Issues Found:
  [MEDIUM] src/api/handler.ts:45
    Missing error handling for network failures

  [LOW] src/utils/format.ts:12
    Consider adding input validation

Suggestion: Add try-catch around the fetch call in handler.ts

How would you like to proceed?
  1. Fix issues and re-evaluate
  2. Commit anyway (1 medium issue)
  3. Abort

Cost Awareness

This command invokes an LLM evaluation, which uses API tokens:

Typical cost: $0.01-0.05 per evaluation (using Haiku)
Larger diffs: May cost more due to increased token usage

When to Use

After significant code changes before committing
When working on unfamiliar parts of the codebase
For changes that affect security-sensitive code
Before pushing to shared branches

When to Skip

Trivial changes (typos, formatting)
Documentation-only changes
When you've already manually reviewed thoroughly
When iterating quickly on a feature branch

Integration with Git Hooks

For automatic evaluation on every commit, see pre-commit-evaluator.sh hook. This command is the manual alternative when you want control over when evaluation runs.