tutor

tutor is a skill for Claude Code, Codex from nicograef/handbook. It costs 124 tokens per session (1,774 once invoked), scanned A, original, MIT.

An interactive tutor for learning a subject, an external tool or specification, or a codebase. It teaches through quizzes with hints and keeps progress for each topic across sessions.

In plain words
What is it for?
Use it when you explicitly want training on a topic or codebase through single-choice, multiple-select, or free-text questions.
Why use it?
It replaces passive explanations with guided practice, while keeping track of review items and previous progress.

Skill for Claude CodeCodex

Part of the handbook plugin — 23 skills, 1 agent, 1 hook 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/nicograef/handbook/tutor
Any agent
npx skills add nicograef/handbook --skill tutor
Clone the repo
git clone --depth 1 https://github.com/nicograef/handbook

Made for: Claude Code, Codex.

Or install handbook, the plugin that ships this one along with the rest of its 23 skills, 1 agent, 1 hook.

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 tutor

README.md
[![agentmods](https://agentmods.dev/badge/skills/nicograef/handbook/tutor.svg)](https://agentmods.dev/skills/nicograef/handbook/tutor)
Your own site
<a href="https://agentmods.dev/skills/nicograef/handbook/tutor"><img src="https://agentmods.dev/badge/skills/nicograef/handbook/tutor.svg" alt="Measured on agentmods" height="20"></a>
Per session 124 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,774 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 $0.00124 $0.01774
Opus 5 $0.00062 $0.00887
Sonnet 5 $0.00025 $0.00355
Haiku 4.5 $0.00012 $0.00177

Measured yesterday against content hash a6b60df4b40b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

tutor 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 yesterday.

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.

.claude/skills/tutor/SKILL.md · 139 lines

How it starts

The opening of the file, as written. The whole thing — 139 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Tutor

Workflow

1. Scope the session

  1. Identify the subject and its source:
    • Model knowledge — established topics.
    • Local files or code — the user pointed at paths.
    • Web research — niche, recent, or version-sensitive topics.
    • Fetch authoritative sources for those rather than trusting memory.
  2. Check for existing state: ls ~/.claude/tutor/ (see session-state.md).
  3. If the topic exists, offer to continue — due review items come first.
  4. Ask one structured round, a single AskUserQuestion call, no more:
    • Familiarity — new / some / refresher.
    • Goal — deep understanding / interview prep / working knowledge.
    • Length — default ~10 questions.
  5. Then state the rules of the game once:
    • Attempt before help.
    • Hints are questions.
    • The answer is revealed only after two failed scaffold rounds.

2. Build the question bank

  • Spawn one general-purpose subagent to digest the material and write the session files.
  • Follow the brief in session-state.md; it lists the inputs to pass.
  • Give the subagent ${CLAUDE_SKILL_DIR}/session-state.md and ${CLAUDE_SKILL_DIR}/question-design.md to read first.
  • Reason 1 — subagent file writes never render in the main conversation, so the answer key stays off-screen.
  • Reason 2 — a pre-committed key makes grading honest: the answer is fixed before the learner answers.

3. Quiz loop

For each item, interleave concepts and mix formats per question-design.md.

  1. Pick the next item from bank.json only.
    • Due-queue entries first, each served by a not-yet-asked item on the same concept.
    • Then unasked items.
    • Never re-ask an item graded in an earlier session.
    • Sole exception: it serves a due entry and no fresh same-concept item exists.
    • Never open key.json before the learner commits an answer.
  2. Choice items → one AskUserQuestion call.
    • Question 1 is the item; options verbatim from the bank, order pre-shuffled.
    • Question 2 is confidence: Sure / Likely / Guessing.
    • Free-text items → ask in chat; the learner answers in their own words.
    • Free-text items add the same confidence call; grade only once both are given.
  3. After the learner commits, look up only that item's key entry: jq '.items["<id>"]' key.json.
  4. Grade against the key:

Read the full file on GitHub · 139 lines

Files

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.

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. yesterday Changed · -11 lines a6b60df4b40b
  2. 4d ago First seen · 150 lines · 124 tokens per session scan A 4f41b17dc51b

Subscribe to this mod's changes

tutor is a skill published in the GitHub repository nicograef/handbook (2 stars, last pushed 2d ago), licensed MIT. It adds 124 tokens to every session and 1,774 once invoked, about $0.0006 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 2026-08-31.

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