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.
npx skills add OutlineDriven/outline-driven-development --skill explain-conceptgit clone --depth 1 https://github.com/OutlineDriven/outline-driven-developmentWrote 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.
[](https://agentmods.dev/skills/outlinedriven/outline-driven-development/explain-concept)<a href="https://agentmods.dev/skills/outlinedriven/outline-driven-development/explain-concept"><img src="https://agentmods.dev/badge/skills/outlinedriven/outline-driven-development/explain-concept/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/outlinedriven/outline-driven-development/explain-concept"><img src="https://agentmods.dev/badge/skills/outlinedriven/outline-driven-development/explain-concept.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00064 | $0.01448 |
| Opus 5 | $0.00032 | $0.00724 |
| Sonnet 5 | $0.00013 | $0.00290 |
| Haiku 4.5 | $0.00006 | $0.00145 |
Grade A, and why
explain-concept 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 5d 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.
How it starts
The opening of the file, as written. The whole thing — 66 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Explain concept
Contract
| Field | Bound contract |
|---|---|
| Trigger | A concept needs making clear not practising; explain simply, why does this exist, draw it, what is the difference, or simplify for a beginner (ELI5). |
| Authority | Read-only: no file, VCS, credential, paid, published, deployed, or remote mutation. Reading files, one web citation search for the origin angle, and a transient diagram render that leaves no artifact are the only outward operations. |
| Side effect | Chat output only: a one-screen explanation for the chosen angle, one authored diagram for the picture angle, one citation search for the origin angle. Nothing is written to any file or repository. |
| Done | A single-angle explanation is presented in chat, grounded in sources or with unanchored claims marked, and the user is prompted to restate or verify where the angle requires it. |
Inputs
The concept to explain must be supplied. An explicit angle argument (intuition, motivation, origin, picture, contrast, or simplify) is optional; the request wording selects the angle when the argument is absent. The grounding source is CORPUS.md when it exists; otherwise, use the source named in answer to the one-time grounding question in the procedure.
Procedure
-
Pick the one angle for this run. An explicit argument overrides the table; no match means intuition.
The learner asks Angle "what is really going on", "I don't get it", "explain it simply" intuition "why does this exist", "what problem does it solve", "why not just X" motivation "where did this come from", "who came up with it", "what did it replace" origin "draw it", "what does it look like" picture "what is the difference", "when do I use X instead of Y" contrast "ELI5", "explain like I am five", "simplify this", "plain language" simplify Done when: one angle is picked and stated.
-
Ground every claim about the concept. When
CORPUS.mdexists, cite its anchor for each claim; when a claim is not in the corpus, say so in the sentence that makes it. With noCORPUS.md, ask once which source to ground in, then proceed and mark unanchored claims the same way in the sentence that makes them. Done when: every claim is grounded or marked unanchored in its own sentence.
What ships with it
2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 5d ago First seen · 66 lines · 64 tokens per session scan A ce3664992de0
explain-concept is a skill published in the GitHub repository OutlineDriven/outline-driven-development (52 stars, last pushed 3d ago), licensed Apache-2.0. It adds 64 tokens to every session and 1,448 once invoked, about $0.0003 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 2026-09-03.
Other skills, from other repositories
book-to-skill
Use when the user names one book, course, paper, or source document and asks to distill it into a reusable skill. Classifies the source as procedure or reference, writes an attributed SKILL.md, and proves its routing. Not for a folder of sources — use map-corpus.
drill
Use when a concept needs practising rather than explaining: run a scaffolded exercise from worked example to independent problem, quiz the learner, run spaced recall over what they cleared, or probe for the gaps blocking what they want next. For explanation, use explain-concept; for an end-to-end build, use capstone.
writing-lean-proofs
Use when asked to design, write, review, refactor, lint, or performance-diagnose Lean 4 proofs, libraries, or tactics. Not for non-Lean code or changes outside source, API, proof, or linter scope.
scaffold-exercises
Use when a course needs numbered problem, solution, and explainer scaffolds. Creates type-specific files with non-colliding names, populates them, and validates with the course linter. Not for a CLI or Next.js project scaffold — use scaffold-cli or scaffold-nextjs.
explain-concept
Use when a concept needs making clear rather than practising: build the intuition, explain why it exists and what it replaced, trace where it came from, draw it, or contrast it against what it gets confused with. For exercises and grading, use drill.
capstone
Use when the user is ready to apply what they learned to something real: scope a project sized to what they have cleared, write the brief with milestones and a done test, then judge the finished work against it. For single-concept exercises and quizzes, use drill.