Explain

Purpose

Explain one thing, once, in genuinely plain words. The object can be a concept, a piece of code, an error, an architecture, or the assistant's own previous output. The core move is an altitude drop: land the explanation at the lowest useful altitude first, a concrete analogy, zero jargon, then layer altitude back up only when the user asks for it. The Feynman technique is the method.

Use when: the user signals they didn't follow something, I don't get it, explain simply, what does this actually mean, rephrase that. Skip when: the user wants ongoing, multi-session coaching with persistent state (hand off to /education:teach); a plain inline answer already lands (just answer).

This skill auto-invokes (no disable-model-invocation) because "I don't get it" should reach it without the user naming a command. Auto-trigger is best-effort; /education:explain is the guaranteed path.

The core move. Plain-language first pass

1. Identify the object. With an argument, that is the thing. Empty argument → the previous assistant response (see "Empty argument" below). Done when you can name the object in one sentence, or, on a cold start with no prior assistant message, have asked what to explain instead of guessing.
2. Ground it, don't recall it. Re-read the actual artifact this turn, the message just sent, the file, the error text, the code. For an external concept, fetch a primary source rather than leaning on parametric memory (plugin doctrine: knowledge is grounded, not remembered). Done when this turn's explanation cites a specific passage, file, error text, or fetched primary source you re-read here. A recalled paraphrase does not count.
3. Drop to plain. One concrete analogy from everyday life. No jargon, no term that itself needs prior knowledge. Short. If a technical word is unavoidable, define it inline in ordinary words the first time. Done when the explanation contains one everyday analogy whose structure maps to the object, a "what it's actually doing" line, and no leftover term that is not defined inline in ordinary words.
4. Close with the handoff line (see "Handoff"). Done when the response ends with the single standard /education:teach invitation line.

Lead with the analogy and the "what it's actually doing," not with vocabulary.

Empty argument. Anaphora default

When invoked with no argument, the object is the assistant's own previous response. The thing the user is reacting to. I don't get it needs no topic named. Re-read that prior message, find the part most likely to have lost the reader (the densest jargon, the biggest leap), and drop that to plain words. Do not ask "explain what?" when the conversation makes the referent obvious. But when there is no prior assistant message to resolve the anaphora against, a cold start where the user opens the conversation with I don't get it and nothing has been said yet, do not hallucinate a referent: ask "What would you like explained?" instead of proceeding blind.

Altitude layering. On request only

Start at rung 1. Climb only when the user asks ("go deeper", "more precise", "I actually know X"). Never front-load a higher rung.

Offer the next rung as a one-line invitation, not a wall of text: "That's the plain version, want the high-school one?"

Feynman gap check

The plain-language pass is a comprehension self-test, not a rewording service. If you cannot shed the jargon, if the only "explanation" you can produce still leans on the very terms the user didn't follow, or on hand-waving, that is a detected understanding gap, on the explainer's side. Surface it honestly rather than papering over it: name the specific part you cannot yet reduce and why, and ground harder (re-read the source, fetch the primary reference) before claiming to explain it. A confident-sounding restatement of jargon is the failure mode this check exists to catch.

Success condition (original-ask invocations only)

When the explanation serves a task the user was stuck on, the success test is their next prompt: it names what they mean in the newly plain terms instead of re-gesturing at the confusion. Judge the explanation by that, and shape rung-2 vocabulary entries so the user can reuse them. A bare comprehension ask with no task behind it ("I don't get it", full stop) has no next-prompt contrast; this check does not apply there.

Handoff to education:teach

Close every explanation with a single lightweight line offering the multi-session path, the first-party sibling in this same plugin:

Want to actually learn this, not just get past it? /education:teach topic <x> runs a multi-session coached deep-dive.

One line, standard close. explain is one-shot; teach is the persistent, mission-driven coach when the user wants ongoing depth or practice.

Gotchas

• Don't climb unasked. The default is rung 1. Delivering the peer-level explanation first defeats the point, the user already didn't follow the peer-level version.
• Anaphora referent is the assistant's output, not the user's. Empty argument explains what the assistant just said, which the user is reacting to.
• Analogy must actually map. A decorative analogy that breaks under one step of pressure is worse than none. Pick one whose structure mirrors the real thing.
• Ground before you simplify. Simplifying a fact you recalled wrongly produces a confident, plain, wrong answer. Re-read or fetch first.

What this skill does NOT do

• Not multi-session coaching. No workspace, mission, glossary, or persistent learning state. When the user wants ongoing tutoring, hand off to /education:teach.
• Not teach's explain action. /education:teach explain <concept> writes a durable lesson into an active teach learning workspace. This skill, /education:explain, is a standalone one-shot with no workspace. Namespacing keeps them distinct; on "I don't get it" only this skill auto-fires (teach sets disable-model-invocation).
• Not a rewording service. If the jargon can't be shed, that's a gap to surface (Feynman gap check), not a synonym to swap in.
• Not a picture. This skill changes altitude and stays in prose. When the user wants a visual explainer instead, a diagram rather than a paragraph, that is the sibling /education:eli5; invoke it via the Skill tool. Its floor is fixed at zero prior knowledge and does not climb, which is the trade it makes for the medium.