| name | amend |
| description | Amend the last git commit with a useful, descriptive message. Use when you want to rewrite a commit message, amend commit description, or improve the last commit message. |
Amend Last Commit
Rewrite the last commit message with a clear, descriptive summary based on the actual changes.
Arguments
$ARGUMENTS - Optional: specific instructions for the commit message (e.g., "mention the performance improvement")
Context
- Current branch: !
git branch --show-current
- Last commit: !
git log -1 --format="%H %s" 2>/dev/null | head -1
- Last commit body: !
git log -1 --format="%b" 2>/dev/null | head -20
- Diff stat: !
git diff HEAD~1 --stat 2>/dev/null | head -30
Instructions
Step 1: Understand the changes
- Read the diff of the last commit:
git diff HEAD~1 (full diff, not just stat)
- Read any files that were added or significantly changed to understand their purpose
- Check the current commit message — if it's already descriptive and accurate, tell the user and stop
Step 2: Draft the message
Write a commit message following this structure:
Subject line (first line):
- Imperative mood ("Add", "Fix", "Update", not "Added", "Fixes")
- Under 72 characters
- Summarize WHAT changed and WHY at a high level
- No trailing period
Body (separated by blank line, optional but preferred for non-trivial changes):
- Explain what the change does and why it was made
- Wrap lines at 72 characters
- Focus on context that isn't obvious from the diff
- Skip the body for truly trivial changes (typo fixes, version bumps)
Step 3: Amend the commit
Run git commit --amend with the new message. Use a HEREDOC to pass the message:
git commit --amend -m "$(cat <<'EOF'
Subject line here
Body paragraph here explaining the change in more detail.
EOF
)"
Step 4: Confirm
Show the user the new commit with git log -1 so they can verify.
Rules
- Never change the commit contents — only the message. Do not stage or unstage files.
- Preserve co-author trailers from the original message if present.
- If the working tree has staged changes, warn the user that
--amend will include them, and ask before proceeding.
- If
$ARGUMENTS contains specific instructions, incorporate them into the message.
