Write a PR Description

A good PR description gets reviewed in 10 minutes. A bad one (or none) gets stalled, rubber-stamped, or starts a thread of clarifying questions. This skill is the template.

When to use

• Opening a non-trivial PR (>50 lines, new behavior, anything risky).
• Reviewing a PR with a "see commits" or auto-generated description and asking the author to expand.
• Writing the PR description before opening, so the description shapes the implementation.

When NOT to use

• Trivial PRs (typo, dependabot bump, one-line config tweak) — title is enough.

The template

## What