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 | $0.01555 |
| Opus 5.5 | $0.00012 | $0.00622 |
| Sonnet 5.5 | $0.00006 | $0.00311 |
| Haiku 4.5 | $0.00003 | $0.00155 |
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 today.
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 — 89 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
No when_to_use.
A condition that follows what the skill does is marked Use when <condition>.
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.
Version lives in plugin.json only. Claude Code spec does not allow version in SKILL.md frontmatter.
Sizing
- Size a skill by a deletion pass using a /reduce loop, never a numeric cap.
- Decision tables > prose explanations.
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 | Function hook aka claude code mods |
| 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 |
Before building any unit, count how often its target situation occurs in real session transcripts, and weigh each case by what the miss cost. A rare, cheap situation caps the value whatever the build's accuracy; a planted test prompt proves the mechanism, never the value.
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.
- today Changed 91ab58b4673b
- 4d ago Changed 2e9d7e9f2838
- 11d ago Changed · +6 lines 408f9150dd75
- 16d ago Changed · +2 lines 171d5712f5dc
- 1mo ago Changed · +1 lines 84c5de8ac7a1
- 1mo ago Changed 47dd62956e7c
- 2mo ago Changed · +12 lines fefe10e5c9a3
- 2mo 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 (38 stars, last pushed today), licensed MIT. It adds 31 tokens to every session and 1,555 once invoked, about $0.0001 per session on Opus 5.5. 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.
moo-authoring compared with skills from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| moo-authoringsaadshahd/moo.md | Skill | 38 | today | MIT | A | 31 | Claude Code |
| session-recapsxhmilyoyo/sundayhao-plugins | Skill | 8 | today | Apache-2.0 | A | 39 | Claude Code |
| knowledge-bank-lookupsxhmilyoyo/sundayhao-plugins | Skill | 8 | today | Apache-2.0 | A | 94 | Claude Code |
| kb-ingestsxhmilyoyo/sundayhao-plugins | Skill | 8 | today | Apache-2.0 | A | 152 | Claude Code |
| kb-lintsxhmilyoyo/sundayhao-plugins | Skill | 8 | today | Apache-2.0 | A | 103 | Claude Code |
| session-managersxhmilyoyo/sundayhao-plugins | Skill | 8 | today | Apache-2.0 | A | 49 | Claude Code |
| lark-openapi-explorerDropFan/claude-code-plugins | Skill | 8 | 22d ago | MIT | A | 76 | Claude Code |