explain

explain is a skill for Claude Code, Codex from tim-mccrimmon/structured-context-spec. It costs 18 tokens per session (978 once invoked), scanned A, original, Apache-2.0.

An explanation of why an AI coding assistant needs clear information about your project's decisions, patterns, and architecture.

In plain words
What is it for?
Use it when explaining structured project context to developers who are skeptical or curious about its value.
Why use it?
It addresses code that works alone but conflicts with existing design choices, and reduces the need to repeat the same project background in every session.

Skill for Claude CodeCodex

Part of the scs-vibe plugin — 1 skill 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/tim-mccrimmon/structured-context-spec/explain
Any agent
npx skills add tim-mccrimmon/structured-context-spec --skill explain
Clone the repo
git clone --depth 1 https://github.com/tim-mccrimmon/structured-context-spec

Made for: Claude Code, Codex.

Or install scs-vibe, the plugin that ships this one along with the rest of its 1 skill.

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/tim-mccrimmon/structured-context-spec/explain.svg)](https://agentmods.dev/skills/tim-mccrimmon/structured-context-spec/explain)
Your own site
<a href="https://agentmods.dev/skills/tim-mccrimmon/structured-context-spec/explain"><img src="https://agentmods.dev/badge/skills/tim-mccrimmon/structured-context-spec/explain.svg" alt="Measured on agentmods" height="20"></a>
Per session 18 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 978 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 $0.00018 $0.00978
Opus 5 $0.00009 $0.00489
Sonnet 5 $0.00004 $0.00196
Haiku 4.5 $0.00002 $0.00098

Measured 4d ago against content hash ed282d098c13, 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 4d ago.

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/scs-vibe/skills/explain/SKILL.md · 119 lines

How it starts

The opening of the file, as written. The whole thing — 119 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Invocation Rules

  • User-initiated only: Do NOT invoke this skill unless the user explicitly runs /scs-vibe:explain. Never auto-invoke based on project state or conversation context.

Why Structured Context Matters (For Vibe Coders)

You're explaining the value of structured context to a developer who may be skeptical or just curious.

The Core Message

Keep it practical and relatable. Don't oversell. The message is:

"Claude is smart but doesn't know YOUR system. Without explicit context, it makes confident decisions based on general knowledge - which often codes you into corners. Structured context gives Claude a 'world' to operate in."

Key Points to Cover

1. The Problem (Make It Relatable)

Share scenarios they've probably experienced:

  • "Claude suggested a perfectly reasonable solution... that conflicted with a design decision you made 3 months ago"
  • "Claude built a feature that works in isolation but doesn't fit your existing patterns"
  • "Every new session, you're re-explaining your architecture"
  • "Claude invented an abstraction you now have to maintain, when a simpler approach would have worked"

The root cause: Claude has vast general knowledge but zero knowledge of YOUR specific system. It fills the gaps with reasonable-sounding guesses.

2. The Solution (Keep It Simple)

Structured context = telling Claude about your system BEFORE it starts making decisions.

It's like onboarding a new developer:

  • Here's what we're building
  • Here's how it's structured
  • Here are the patterns we use (and avoid)
  • Here are the constraints you need to know

The key insight: This isn't about making Claude smarter. It's about giving it the information it needs to apply its intelligence appropriately.

3. What Goes in Structured Context

The essentials:

  • System Overview: What does this do? Who uses it?
  • Architecture: How is it structured? What are the key components?
  • Tech Stack: What specific technologies and why?
  • Patterns: What patterns do we use? What do we avoid?
  • Constraints: What limits must Claude respect?

Read the full file on GitHub · 119 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. 4d ago First seen · 119 lines · 18 tokens per session scan A ed282d098c13

Subscribe to this mod's changes

explain is a skill published in the GitHub repository tim-mccrimmon/structured-context-spec (19 stars, last pushed 2mo ago), licensed Apache-2.0. It adds 18 tokens to every session and 978 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 2026-08-30.