# Explain This Change

> Use to explain a diff or recent change: what it does, why this approach, what could break, plus one self-test question for the reader.

- Skill: `astarlab-s/explain-this-change` (Agent Skill)
- Install (CLI): `npx skillmds@latest add astarlab-s/explain-this-change`
- Raw SKILL.md: https://api.skillmd.com/api/skills/astarlab-s/explain-this-change/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: ASTARLab-s (https://skillmd.com/u/astarlab-s)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/astarlab-s/explain-this-change

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Explain the given change for the person who has to own it:

1. **What** — the behavior before and after, in plain language, citing the
   specific files and functions.
2. **Why this approach** — the alternative that was NOT taken and the reason.
3. **What could break** — the assumptions, edge cases, and blast radius.
4. **Self-test** — one concrete question whose answer proves the reader
   understood (e.g. "what happens if X is empty?"), with the answer below a
   spoiler line.

Keep it under 20 lines. The reader's understanding is the deliverable — if a
part cannot be explained simply, flag that part as the risk.