gh-schpet-jjagent/commands/describe.md

description, model, allowed-tools

description	model	allowed-tools
Generate a commit description for the current session's jj change	claude-haiku-4-5	Bash(jjagent:*), Bash(jj:*)

jj-describe

Generate a commit description for a Claude session's jj change

instructions

You must follow these steps to create a proper commit message:

1. Determine session ID:

   • Use the session ID from the system reminder (current session)
   • Store the session ID for use in subsequent steps

2. Check if a change exists for the session:

   • Run: jjagent change-id <session-id> to check if a change exists
   • IMPORTANT: If the command fails or returns an error, immediately stop and inform the user: "No jj change exists for this session yet. There's nothing to describe."
   • Do NOT proceed to the next steps if no change ID is found

3. Gather context:

   • Run: jj diff -r "$(jjagent change-id <session-id>)" to see ONLY the diff
   • Review the diff to understand what was actually changed
   • Review the conversation/context to understand why a change was made
   • Do NOT read the existing commit message - it will be replaced entirely

4. Generate a NEW commit message:

   • First line (subject):
     • 50 characters or less
     • Capitalize the first letter
     • Use imperative mood (e.g., "Add feature" not "Added feature" or "Adds feature")
     • No period at the end
     • Concise summary of the change, not just "jjagent: session "
   • Second line: Blank
   • Body (if needed):
     • Wrap at 72 characters
     • Provide more detailed explanatory text with technical details, but stay concise
     • Explain what and why, not how the code works
     • Use bullet points for multiple items if appropriate
     • Blank lines separate paragraphs

5. Update the description:

   • Run: jjagent describe <session-id> -m "your commit message here"
   • Do NOT include any trailers (Claude-session-id, etc.) - they are preserved automatically
   • Only include the subject line and body
   • Use a heredoc or proper quoting to preserve formatting
   • Note: This is the Rust CLI tool command, not the slash command

6. Show the final change

   • Run: jj show "$(jjagent change-id <session-id>) -s and show the user direct output formatted as a code block

Example commit message (what you pass to jjagent describe):

Add SessionStart and UserPromptSubmit hooks

Implement hook handlers that inject the session ID into Claude's
context at the start of a session and re-inject it when it's been
lost from the recent transcript.

- Add HookSpecificOutput structure for passing context to Claude
- Implement handle_session_start_hook to inject session ID
- Implement handle_user_prompt_submit_hook to re-inject when needed
- Add comprehensive tests for both hook handlers

Note: Do NOT include the Claude-session-id trailer - it's preserved automatically.

Important notes:

• Do NOT use the generic "jjagent: session " format for the subject line
• DO write a concise summary in the subject, with technical details in the body
• DO analyze the actual changes and write a meaningful, specific subject
• DO use imperative mood ("Add", "Fix", "Refactor", not "Added", "Fixed", "Refactored")
• DO keep the subject line to 50 characters or less
• DO wrap body lines at 72 characters
• Do NOT include trailers - they are preserved automatically by jjagent describe
• Do NOT look at the existing commit message - generate a fresh one from the diff