SkillValidated

Explain-this-change — comprehension as a deliverable

A skill that turns any diff into a structured explanation: what changed, why this approach, what could break, and one question to test your own understanding — so comprehension keeps pace with acceptance.

$cosq add explain-this-change

Free, works signed out. No CLI? Copy the file below into your repo — same result.

Why this one

Passive acceptance lowered comprehension while engaged interaction preserved skill (Anthropic skill-formation study).

How to use it

  1. 1Invoke on any change you could not re-implement yourself
  2. 2Answer the self-test question before accepting

What gets installed

Pick your tool to preview the exact file cosq add writes — byte-for-byte. Prefer copy-paste? Use the copy button on the file.

.claude/skills/explain-this-change/SKILL.md(created)
---
name: explain-this-change
description: 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.
---

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.