explain

explain is a skill for Claude Code, Codex from FlorianBruniaux/claude-code-plugins. It costs 15 tokens per session (966 once invoked), scanned A, original, MIT.

A skill for explaining code, technical concepts, or system behavior at different levels of detail.

In plain words
What is it for?
Understanding files, functions, modules, architecture, and the flow of data or control.
Why use it?
It turns unfamiliar implementation details into an explanation matched to the reader's needs.

Skill for Claude CodeCodex

Part of the session-tools plugin — 8 skills, 6 commands, 1 agent, 1 plugin shipped together

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/florianbruniaux/claude-code-plugins/explain
Any agent
npx skills add FlorianBruniaux/claude-code-plugins --skill explain
Clone the repo
git clone --depth 1 https://github.com/FlorianBruniaux/claude-code-plugins

Made for: Claude Code, Codex.

Or install session-tools, the plugin that ships this one along with the rest of its 8 skills, 6 commands, 1 agent, 1 plugin.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for explain

README.md
[![agentmods](https://agentmods.dev/badge/skills/florianbruniaux/claude-code-plugins/explain.svg)](https://agentmods.dev/skills/florianbruniaux/claude-code-plugins/explain)
Your own site
<a href="https://agentmods.dev/skills/florianbruniaux/claude-code-plugins/explain"><img src="https://agentmods.dev/badge/skills/florianbruniaux/claude-code-plugins/explain.svg" alt="Measured on agentmods" height="20"></a>
Per session 15 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 966 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00015 $0.00966
Opus 5 $0.00008 $0.00483
Sonnet 5 $0.00003 $0.00193
Haiku 4.5 $0.00002 $0.00097

Measured today against content hash c30dc3ef940b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

explain scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured today.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

plugins/session-tools/skills/explain/SKILL.md · 175 lines

How it starts

The opening of the file, as written. The whole thing — 175 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Code Explainer

Explain code, concepts, or system behavior with adjustable depth levels.

Purpose

Get clear explanations of:

  • How specific code works
  • Why certain patterns are used
  • What a system/module does
  • Architectural decisions and trade-offs

Instructions

Step 1: Determine Scope

Identify what needs explanation:

  • File: Entire file structure and purpose
  • Function/Method: Specific implementation details
  • Concept: Architectural pattern or design decision
  • Flow: How data/control moves through the system

Step 2: Assess Complexity

Simple (1-2 min read)     → Quick summary, key points only
Standard (3-5 min read)   → Purpose, how it works, key decisions
Deep (10+ min read)       → Full breakdown, alternatives, trade-offs

Step 3: Gather Context

# For file explanations
head -50 "$FILE"  # See imports and structure

# For function explanations
grep -A 30 "function $NAME\|def $NAME\|fn $NAME" "$FILE"

# For module explanations
ls -la "$DIR"
cat "$DIR/index.ts" 2>/dev/null || cat "$DIR/__init__.py" 2>/dev/null

Step 4: Structure the Explanation

Output Format


📖 Explanation: [Target]

Scope: [file/function/concept/flow] Depth: [simple/standard/deep]

What It Does

[1-3 sentences describing the purpose]

How It Works

[Step-by-step breakdown appropriate to depth level]

Key Decisions

Decision Why Alternative
[choice made] [reasoning] [what else could work]

Example Usage

// How to use this correctly

Related Code

  • path/to/related.ts - [relationship]
  • path/to/dependency.ts - [relationship]

💡 Learning Notes (if --learn flag)

[Additional context for understanding the broader pattern]


Depth Levels

Simple (/explain --simple)

**validateUser()** checks if the user object has required fields
(email, password) and returns a boolean. Uses regex for email format.

Read the full file on GitHub · 175 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. today First seen · 175 lines · 15 tokens per session scan A c30dc3ef940b

Subscribe to this mod's changes

explain is a skill published in the GitHub repository FlorianBruniaux/claude-code-plugins (40 stars, last pushed 3d ago), licensed MIT. It adds 15 tokens to every session and 966 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-04.

Related

Other skills, from other repositories

replay-learnings

Surface past learnings relevant to the current task before starting work. Searches correction history, recalls past mistakes, and applies prior patterns. Use when starting a task, saying "what do I know about", "previous mistakes", "lessons learned", or "remind me about".

rohitg00/pro-workflow · 61 tokens

agentic-learning

A learning partner skill grounded in neuroscience and philosophy. Use when you want to actually learn a concept (not just get an answer), quiz yourself on a codebase, reflect on what you built, brainstorm a design collaboratively, practice productive struggle on a hard problem, journal a decision with its alternatives…

FavioVazquez/learnship · 110 tokens

learnship

You are working inside a project that uses learnship — a multi-platform agentic engineering system for building real products with spec-driven workflows, integrated learning, and impeccable design.

FavioVazquez/learnship · 0 tokens

zhuoyu-workshop

Student project delivery and packaging workflow for Codex. Use when the user needs help with Chinese university student projects, course projects, innovation training projects, competitions, capstones, graduation projects, project defense decks, closing reports, README/GitHub showcase materials, software copyright…

handsomeZR-netizen/zhuoyu-workshop-skill · 81 tokens

diffscope

코드 변경을 학습용 브리핑으로 바꾼다. 변경 지도 시각화 + 동작 차이 추적 + Python 문법 해설을 한 번에 터미널에 출력한다. Stop hook이 "[diffscope] 이번 턴에 소스 파일 N개가 변경되었다"라는 지시와 함께 patch 경로를 넘기면 반드시 이 스킬을 사용할 것. 사용자가 "방금 뭐 바뀐 거야", "이번 변경 설명해줘", "변경사항 설명", "이 코드 이해 안 돼", "브리핑", "다시 설명해줘", "더 자세히", "쉽게 다시", "문법만 다시", "로직만 다시", "아까 그 변경 다시 보여줘", "자동 분석 꺼줘/켜줘"라고 할 때도 이…

SWHee/diffscope · 292 tokens

learn

Use at the end of T3 work, after an incident/rollback, or when the user asks for a retro — turns what happened into recorded learnings that live in the repo (CHANGELOG entry, typed LEARNINGS.md entries, follow-up tasks, and — only with explicit user approval — new RULES).

AbdurRafay2004/handoff · 66 tokens