/pr-writer

name: pr-writer
description: Create or refresh reviewer-facing PR titles and descriptions. Use when opening a PR, updating its title or body, or preparing branch changes for review.

PR Writer

Write the PR body as a cover note for reviewers, not a changelog, template, validation log, or file-by-file summary.

Inspect the Change

Requires authenticated `gh`. Inspect the current branch, working tree, PR, base branch, commits, and full diff:

git branch --show-current
git status --porcelain
gh pr view --json number,title,body,url,baseRefName,headRefName
gh repo view --json defaultBranchRef

If `gh pr view` reports that no PR exists, continue with first-time PR creation. For an existing PR, use its `baseRefName`; otherwise use the repository default branch. Set `BASE`, then inspect:

git log "$BASE"..HEAD --oneline
git diff "$BASE"...HEAD

If on `main` or `master`, create a feature branch first. Ensure intended changes are committed and review the whole branch diff, not only the latest commit or existing PR text.

Core Rules

• Describe concrete changed behavior, affected surfaces, and reviewer impact

before implementation detail.

• Explain motivation, risk, tradeoffs, migration, or review focus only when

useful.

• Use the smallest structure that makes the change easier to review.
• Replace internal prompt or process terminology with specific behavior.
• When refreshing a PR, rewrite around the current full diff without narrating

review history.

Titles

Use `<type>(<scope>): <subject>` or `<type>: <subject>`.

Allowed types: `feat`, `fix`, `ref`, `perf`, `docs`, `test`, `build`, `ci`, `chore`, `style`, `meta`, `license`, and `revert`.

• Describe the dominant full-branch change with the narrowest accurate type

and scope.

• Use `!` only when the change breaks an external contract, and explain the

affected surface in the body.

• Avoid vague subjects such as `update`, `cleanup`, `misc`, `fix stuff`,

or `address feedback`. Do not add a trailing period.

• Keep an existing title only when it still describes the whole diff.

Body Shape

Choose the minimum useful shape:

| Change | Include | |--------|---------| | Small or obvious | One concise paragraph without headings. | | Feature, bug fix, or refactor | Changed behavior and effect; add root cause, unchanged behavior, or non-obvious approach when relevant. | | Contract or breaking change | Affected API, schema, payload, config, permission, storage, or CLI surface; include compatibility and migration guidance. | | Operational, visual, or workflow change | User/operator effect, measured impact, failure modes, or flow when useful. | | Broad, generated, or cross-cutting change | Organizing principle, why the breadth is necessary, and where review should start. |

Default:

<What changed and what effect it has.>

<Why the approach, risk, migration, or review focus matters, if not obvious.>

For review-feedback updates, describe the resulting PR as a whole rather than the sequence of revisions.

Reviewer Aids

Use an aid only when it reduces reviewer reconstruction work:

• A compact before/after or interface example for changed contracts.
• A small Mermaid diagram for async flows or state transitions.
• A screenshot or recording note when visual evidence exists.
• A rollout, compatibility, risk, or review-order note when reviewers or

adopters need it.

Introduce an artifact with one sentence explaining what reviewers should notice. Omit it when prose is clearer.

Boundaries

• Do not add default `Summary`, `Changes`, or `Test Plan` sections.
• Omit routine validation unless it changes risk assessment or explains

meaningful regression coverage. For docs, skills, copy, or config changes, omit it by default.

• Do not paste commands, CI logs, validation dumps, commit logs, placeholders,

or exhaustive file lists.

• Never include customer or organization names, user emails, support ticket

contents, secrets, or PII.

• Use issue references only when verified from user input, branch names,

commits, PR discussion, or tracker output. `Fixes <issue>` closes; `Refs <issue>` only links.

Create or Update

Create new PRs as drafts. Write the body to a temporary Markdown file, then run:

gh pr create --draft --title '<title>' --body-file /tmp/pr-body.md

Update existing PRs with `gh api`:

gh api -X PATCH repos/{owner}/{repo}/pulls/PR_NUMBER \
  -f title='<title>' \
  -F body=@/tmp/pr-body.md

Refresh the title and body when follow-up commits materially change scope, approach, breaking behavior, risk, migration, or review expectations. Skip typo-only, formatting-only, and rename-only follow-ups.

Examples

Small change:

The AI Customizations section now starts collapsed so it does not consume
sidebar space before users need it. Expanding it preserves the existing saved
preference behavior.

Breaking contract:

Run logs now emit chunk-level records instead of one skill-level record.
Consumers that read top-level `findings` must iterate over
`chunk.findings` for each record.

Before:

```json
{"skill": "security-review", "findings": [...]}

After:

{"schemaVersion": 1, "chunk": {"index": 1, "findings": [...]}}