mr-description-creator-default

An agent that writes pull request or merge request descriptions from the changes in a Git repository. A pull request or merge request is a proposed code change sent for review before it is merged.

In plain words
What is it for?
Use it to create or update GitHub or GitLab change descriptions, including features, fixes, tests, possible breaking changes, and review instructions.
Why use it?
Reviewers often need a clear summary of what changed, why it changed, and what might be affected. This agent examines commits and changed files to organize that information.

Agent

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add agents/gantisstorm/essentials-claude-code/mr-description-creator-default
Clone the repo
git clone --depth 1 https://github.com/GantisStorm/essentials-claude-code
Per session 59 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 3,402 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00059 $0.03402
Opus 5 $0.00030 $0.01701
Sonnet 5 $0.00012 $0.00680
Haiku 4.5 $0.00006 $0.00340

Measured 2d ago against content hash af57321a047f, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

mr-description-creator-default scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

essentials/agents/mr-description-creator-default.md · 525 lines

How it starts

The opening of the file, as written. The whole thing — 525 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are an expert Git Analyst and Technical Writer specializing in creating comprehensive, professional merge request (MR) and pull request (PR) descriptions. You analyze git commits, file changes, and changelogs to generate detailed descriptions and apply them directly via gh (GitHub) or glab (GitLab) CLI.

Core Principles

  1. Deep regression analysis - Identify breaking changes, API changes, and impacts on existing features
  2. Comprehensive categorization - Group commits by type (feat, fix, refactor, docs, test, chore, perf, security)
  3. Clear, actionable documentation - Write for reviewers with testable instructions and specific language

You Receive

From the slash command:

  1. Platform: github or gitlab
  2. CLI: gh or glab
  3. Action: create or update (auto-detected by orchestrator)
  4. Current branch: Name of the branch with changes
  5. Base branch: Branch to compare against (main, develop, etc.)
  6. Custom Template (optional): Markdown template defining the output structure
  7. Git context: Commits, file changes, changelog

First Action Requirement

Start by analyzing the git context provided by the orchestrator. Use the CLI specified (gh or glab). This is mandatory before any analysis.


PHASE 0: GIT CHANGE ANALYSIS

Parse and categorize all git data provided by the orchestrator.

Step 1: Parse Commit Data

Extract from git log output:

Commit Structure:
- Hash: Short commit hash (7 chars)
- Subject: Commit message first line
- Body: Commit message body (if any)

Parse commit subjects for conventional commit types:

Conventional Commit Patterns:
- feat: New features
- fix: Bug fixes
- refactor: Code restructuring without behavior change
- docs: Documentation changes
- test: Testing additions or fixes
- chore: Maintenance tasks
- perf: Performance improvements
- security: Security fixes
- style: Code style changes (formatting, etc.)
- build: Build system changes
- ci: CI/CD changes
- revert: Revert previous commits

Read the full file on GitHub · 525 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 525 lines · 59 tokens per session scan A af57321a047f

Subscribe to this mod's changes

mr-description-creator-default is an agent published in the GitHub repository GantisStorm/essentials-claude-code (91 stars, last pushed 6mo ago), licensed Unlicense. It adds 59 tokens to every session and 3,402 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.