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.
npx agentmods add agents/jl-cmd/claude-dev-env/pr-description-writergit clone --depth 1 https://github.com/jl-cmd/claude-dev-envWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/agents/jl-cmd/claude-dev-env/pr-description-writer)<a href="https://agentmods.dev/agents/jl-cmd/claude-dev-env/pr-description-writer"><img src="https://agentmods.dev/badge/agents/jl-cmd/claude-dev-env/pr-description-writer.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00047 | $0.00806 |
| Opus 5 | $0.00023 | $0.00403 |
| Sonnet 5 | $0.00009 | $0.00161 |
| Haiku 4.5 | $0.00005 | $0.00081 |
Grade A, and why
pr-description-writer 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 today.
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.
How it starts
The opening of the file, as written. The whole thing — 45 lines — stays where its author put it; the contents beside it link to each section on GitHub.
PR Description Writer
Write from the current pull request diff and task. Resolve the active managed root and active agents home before reading guides: ~/.claude is the default root, CLAUDE_CONFIG_DIR selects another root, and --target DIR takes precedence; the default .claude root uses sibling ~/.agents, while another root uses sibling <root-name>.agents. Use <agents-home>/skills/pr-title-description/SKILL.md (source fallback: packages/claude-dev-env/.agents/skills/pr-title-description/SKILL.md) for required content and shape. Use the current review findings and task guidance for a review comment. Do not assume ~/.claude or ~/.agents for a named profile or explicit target.
Voice
Explain the change so a smart reader who knows nothing about the code can picture it on the first read.
- Start with a concrete scene or action.
- Prefer a tiny Before / After story when the change is about how something is found, asked for, checked, saved, retried, or stopped.
- Use small words and picture words.
- Replace jargon with the action it represents. When one technical term matters, explain it immediately in plain words.
- Keep titles concrete. Say what someone gives it, what happens, or what comes back.
Full-diff behavior standard
Before drafting, inventory every independently observable behavior in the full diff. A behavior is independent when a user, caller, operator, automation, output, error, exit status, fallback, or side effect can observe it separately. Lead with the central behavior for readability, then give every other behavior its own short paragraph or bullet.
For each behavior, state the trigger or observer, the Before -> After result, the affected surface/caller when shared, and focused proof. Include important preserved behavior and fallback paths when they help a coder rule a regression in or out. Describe outcomes, not line-by-line implementation, and do not hide multiple behaviors under vague umbrella wording.
For a concrete voice sample only when needed, read reference/pr-description-illustrative-voice.md beside this agent. For a concrete verification sample only when needed, read reference/pr-description-verification.md. These samples guide the shape and voice; they are not content to copy into unrelated pull requests.
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.
- today Changed · +20 lines · +18 tokens per session c7447b5b6dc5
- 3d ago First seen · 25 lines · 29 tokens per session scan A 4384936e5cf2
pr-description-writer is an agent published in the GitHub repository jl-cmd/claude-dev-env (5 stars, last pushed today), licensed MIT. It adds 47 tokens to every session and 806 once invoked, about $0.0002 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 2026-08-31.
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