describing-prs

name	describing-prs
description	Generate a PR description for the current branch. Writes Markdown to .git/magit/posts/new-pullreq for use with magit-forge.
allowed-tools	Bash(~/.agents/skills/describing-prs/scripts/find-merge-base.py:*)

PR Description Generator

Generate a well-structured PR description for the current feature branch.

When to Use This Skill

Use this skill when:

• Preparing to create a pull request
• Needing a PR description for the current branch
• Integrating with magit-forge for PR creation

Process

1. Determine the base branch

   Run the helper script to find the base branch:

   BASE=$(~/.agents/skills/describing-prs/scripts/find-merge-base.py)
   

   The script outputs a branch name (e.g., origin/main) that represents the base branch for comparison. It handles cases where you branched from another feature branch, not just main/master.

   Options:

   • --fetch: Fetch latest remote refs before determining base branch
   • --debug: Show how the base branch is determined

   Strategy (implemented in the script):

   • Try @{upstream} first (the current branch's configured upstream)
   • Try origin/HEAD (the remote's default branch)
   • Fall back to common defaults: origin/main, origin/master, origin/develop
   • If neither works, find the closest remote branch by commit distance

2. Gather context about the branch

   Using the base branch found above:

   git branch --show-current
   git log --oneline <base-branch>..HEAD
   git diff --no-ext-diff <base-branch>..HEAD --stat
   git diff --no-ext-diff <base-branch>..HEAD
   

3. Analyze the changes

   • Identify the purpose of the changes
   • Group related commits by theme
   • Note any breaking changes or important considerations

4. Generate the PR description

   Write a Markdown file with:

   • Title: A concise summary (will be used as PR title)
   • Summary: 2-3 sentences explaining the overall purpose
   • Changes: Bullet points of key modifications
   • Testing: How the changes were tested (if applicable)
   • Notes: Any reviewer notes, breaking changes, or follow-up items

5. Write to the output file

   Create the directory and write the description:

   mkdir -p .git/magit/posts
   

   Write Markdown content to .git/magit/posts/new-pullreq

Output Format

The generated file should follow this structure:

# <PR Title>

## Summary

<Brief explanation of what this PR accomplishes and why>

## Changes

- <Key change 1>
- <Key change 2>
- ...

## Testing

<How changes were tested, or "N/A" if not applicable>

## Notes

<Any additional context for reviewers, breaking changes, or follow-up work>

Formatting Guidelines

• Wrap all symbols, variables, function names, file paths, and code references in backticks (e.g., myFunction, CONFIG_VALUE, src/utils.ts)
• Use fenced code blocks for multi-line code snippets
• Keep bullet points concise and scannable

Important Notes

• The file path .git/magit/posts/new-pullreq is used by magit-forge
• Always overwrite the existing file if present
• Keep the description concise but informative
• Focus on the "why" more than the "what" (the diff shows the "what")