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 agentmods add instructions/lzfxxx/shadow-tutor/agents-mdgit clone --depth 1 https://github.com/lzfxxx/shadow-tutorWrote 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/instructions/lzfxxx/shadow-tutor/agents-md)<a href="https://agentmods.dev/instructions/lzfxxx/shadow-tutor/agents-md"><img src="https://agentmods.dev/badge/instructions/lzfxxx/shadow-tutor/agents-md.svg" alt="Measured on agentmods" height="20"></a>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 | $0.00796 | $0.00796 |
| Opus 5 | $0.00398 | $0.00398 |
| Sonnet 5 | $0.00159 | $0.00159 |
| Haiku 4.5 | $0.00080 | $0.00080 |
Grade A, and why
shadow-tutor AGENTS.md 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.
How it starts
The opening of the file, as written. The whole thing — 58 lines — stays where its author put it; the contents beside it link to each section on GitHub.
AGENTS.md — repository instructions for coding agents
Shadow Tutor is an in-session post-session tutor delivered as a native skill for both Codex
and Claude Code. The product is skills/shadow-tutor/METHODOLOGY.md (a teaching methodology)
plus thin supporting code. Keep changes small, evidence-checked, and language-neutral.
Layout in one line
skills/shadow-tutor/ is the product — a self-contained skill bundle
(SKILL.md + METHODOLOGY.md + scripts/knowledge.mjs) that every install path
(npx skills add, plugin marketplace, install.sh, npx shadow-tutor install) copies verbatim.
Never fork per-tool copies; plugins/ is generated from it by node bin/cli.mjs build.
Build / test / eval
npm test # node:test unit tests — must stay green
npm run eval:dry # assemble eval prompts without model calls (no quota needed; CI-safe)
npm run eval # real eval via `claude -p` / `codex exec` — simulated-student dialogue + rubric
node bin/cli.mjs build # regenerate plugins/shadow-tutor/ after changing the bundle (CI checks sync)
./install.sh # install the skill into ~/.claude/skills and ~/.codex/skills
There is no build step for the skill itself; everything is plain ESM .mjs and markdown.
Mandatory rules (if/then)
- Before editing
skills/shadow-tutor/(especiallyMETHODOLOGY.md), followdocs/dev/eval-regression.md: run the eval and confirm the rubric score does not drop (must stay ≥13, no regression on existing fixtures). Teaching quality is the product; a silent regression here is the worst failure mode. - When adding a recorded coding session as a test fixture, follow
docs/dev/add-fixture.mdto normalize it and place it undereval/fixtures/{cc,codex}/. - When changing
skills/shadow-tutor/scripts/knowledge.mjs, add or update a case inscripts/knowledge.test.mjsand keepnpm testgreen. - After changing anything under
skills/shadow-tutor/orclaude/commands/, runnode bin/cli.mjs buildand commit the regeneratedplugins/.
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.
- 4d ago First seen · 58 lines · 796 tokens per session scan A baf006a05843
shadow-tutor AGENTS.md is an instructions file published in the GitHub repository lzfxxx/shadow-tutor (4 stars, last pushed 2mo ago), licensed MIT. It adds 796 tokens to every session, about $0.0040 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.
Other instructions, from other repositories
agents AGENTS.md
AGENTS.md instructions for scarletkc/agents, covering agent guidelines, environment, engineering principles, code style and testing.
claude-code-mastery CLAUDE.md
Instructions for ShipWithAI/claude-code-mastery, covering claude.md — claude code mastery course, project overview, course structure, directory layout and teaching methodology: progressive hands-on hybrid.
codex-manager AGENTS.md
AGENTS.md instructions for ewsun22/codex-manager, covering codex manager 项目指令, 产品边界, 隐私与安全, 工程规则 and 开源文档与发布流程.
awesome-grok-build AGENTS.md
Instructions for DominikTobureto/awesome-grok-build, covering agents.md, mission, operating principles, source policy and file conventions.
conforme AGENTS.md
Instructions for maxgfr/conforme, covering project instructions, claude.md, project overview, build & test and architecture.
conforme GEMINI.md
Instructions for maxgfr/conforme, covering claude.md, project overview, build & test, architecture and keeping docs in sync.