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 saadshahd/moo.md --skill moo-authoringgit clone --depth 1 https://github.com/saadshahd/moo.mdWrote 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/saadshahd/moo.md/moo-authoring)<a href="https://agentmods.dev/skills/saadshahd/moo.md/moo-authoring"><img src="https://agentmods.dev/badge/skills/saadshahd/moo.md/moo-authoring/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/saadshahd/moo.md/moo-authoring"><img src="https://agentmods.dev/badge/skills/saadshahd/moo.md/moo-authoring.svg" alt="Reviewed on agentmods" width="80" 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 5.1 | $0.00031 | $0.01139 |
| Opus 5 | $0.00015 | $0.00570 |
| Sonnet 5 | $0.00006 | $0.00228 |
| Haiku 4.5 | $0.00003 | $0.00114 |
Grade A, and why
moo-authoring 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 2d 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 — 80 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Doctrine for authoring moo's own surfaces.
Frontmatter
A skill's frontmatter carries name and description; read any shipped SKILL.md for the current key set. The description is one line, and Claude Code caps it at 1024 characters.
No when_to_use. Claude Code reads that key and renders it dash-joined onto the description, but every other agent copies SKILL.md verbatim and never reads it, so the text deciding when a skill fires would be invisible wherever it is installed outside Claude Code.
A condition that follows what the skill does is marked Use when <condition>. — a finite clause, never a bare noun phrase or a bare dash. The key name was what marked the condition as a condition; in one string nothing else does, and an unmarked trailing clause reads as more of what the skill produces. A description may also open with the condition and stop there, where naming the capability would discriminate nothing.
A skill that stays in this repo declares metadata.internal: true. The skills.sh installer walks the tree and offers every SKILL.md it finds; that flag is what it filters on.
Version lives in plugin.json only (DRY). The official Claude Code spec does not allow version in SKILL.md frontmatter.
Sizing
- Size a skill by a deletion pass, never a numeric cap.
- Put branch-specific content in files the skill opens when the branch is taken, and name them where they are needed.
- Decision tables > prose explanations.
Token Efficiency
- Challenge every sentence: "Does Claude need this?"
- Bullets for enumerable items; a paragraph when the point is one connected argument.
- No vague terminology; pick one term per concept.
Skill Design
Phrase design decisions as "X over Y: reason".
Unit choice — behavior inlines at build, data references at runtime; a skill's firing is probabilistic, so behavior that must run every time is a hook:
| The new thing is... | Unit |
|---|---|
| Data selected per use (catalog, profile, corpus) | Runtime file |
| A trigger + procedure that stands alone | Skill |
| A trigger only the human perceives | Skill with disable-model-invocation: true |
| Behavior that must run every time, deterministically | Hook |
| An unproven idea | hunch skill + HYPOTHESIS.md; graduates or dies |
| Doctrine for this repo's own surfaces | Repo-local skill in .claude/skills/; never ships |
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.
- 2d ago Changed · +12 lines fefe10e5c9a3
- 10d ago First seen · 68 lines · 31 tokens per session scan A 6653797bc2c1
moo-authoring is a skill published in the GitHub repository saadshahd/moo.md (34 stars, last pushed 3d ago), licensed MIT. It adds 31 tokens to every session and 1,139 once invoked, about $0.0002 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.
Other skills, from other repositories
session-recap
Document Claude Code sessions by extracting knowledge into cross-referenced documentation. Triggers on "recap the session", "summarize the work", or after significant code changes.
knowledge-bank-lookup
Delegates knowledge bank lookups to Explore subagents with reflections-first strategy that learns from past mistakes. Checks /reflections/ directory before documentation to extract documented failures to avoid and proven approaches to apply. Automatically triggers when user mentions services ([project-a], [project-b]…
kb-ingest
Ingest external sources into the knowledge bank through interactive study or quick filing. Two modes — Quick (summarize → file) and Study (theme-by-theme deep dive with online research and personal notes → multi-layer KB output → optional blog/slack synthesis). Triggers on "ingest this", "study this article", "add to…
lark-openapi-explorer
A skill for finding and calling Lark APIs that are not already available through existing commands. An API is a defined way for software to request work from another service.
lark-workflow-standup-report
A Feishu (Lark) workflow that combines calendar events with unfinished tasks into a daily schedule summary. Feishu is a workplace collaboration app with calendar and task features.
session-manager
Manage current Claude Code session metadata — set project, tags, and summary on session.md via Obsidian CLI. Use this skill whenever the user wants to tag, categorize, name, label, summarize, or organize the current session. Triggers on phrases like "tag this session", "this was about X", "mark this as", "session…