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 slowdini/slow-powers --skill writing-skillsgit clone --depth 1 https://github.com/slowdini/slow-powersWrote 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/slowdini/slow-powers/writing-skills)<a href="https://agentmods.dev/skills/slowdini/slow-powers/writing-skills"><img src="https://agentmods.dev/badge/skills/slowdini/slow-powers/writing-skills/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/slowdini/slow-powers/writing-skills"><img src="https://agentmods.dev/badge/skills/slowdini/slow-powers/writing-skills.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 | $0.00034 | $0.03802 |
| Opus 5 | $0.00017 | $0.01901 |
| Sonnet 5 | $0.00007 | $0.00760 |
| Haiku 4.5 | $0.00003 | $0.00380 |
Grade A, and why
writing-skills 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 10d 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 — 310 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Writing skills
Overview
Skill development has two phases: drafting (this skill) and evaluation
(slow-powers:evaluating-skills). This skill is your template for authoring a new skill and
your checklist for auditing an existing one — it covers structure, building blocks, description
writing, and rationalization-proofing.
A behavioral draft you didn't measure is a claim you didn't verify. After drafting, hand off to
slow-powers:evaluating-skills to decide whether the change is behavior-shaping (measure it) or
deterministic instruction-following (declare the decision and reasoning, then skip). Default to
measuring; the skip is a narrow, announced exception, not an escape hatch.
Validation checklist
Use your persistent task tracker — one task per item. Works for authoring a new skill or auditing an existing one — copy it into your tracker before you start, then work through the rest of this skill against it.
Draft:
- Name uses only lowercase letters, numbers, hyphens
- Frontmatter has
nameanddescription(under 1024 chars total) - Description starts with "Use when…", is third person, includes triggers/symptoms, and contains NO workflow summary
- Body keeps to one excellent example per concept; no narrative-of-one-session content
- Companion files use the correct directory from "Skill directory layout"; principles stay inline
- Flowcharts only for non-obvious decisions/loops/branches; semantic labels, no code
- Any checklist sits near the top of the body, before the procedural sections it gates
- Body is lean (≤200 lines preferred, 500 max)
Validate (handoff to slow-powers:evaluating-skills):
- Decide whether the change is behavior-shaping or deterministic, and announce the decision and reasoning (see "Choosing to test with evals"). Default to behavior-shaping when unsure.
- If behavior-shaping (or the user opts in): author
evals/evals.jsonwith 2–3 realistic prompts - For discipline-enforcing skills, write pressure prompts combining multiple pressures, plus at least one seeded case (embeds a prior transcript) alongside a cold contrast case
- Run the eval. Iterate until the with-skill pass rate is materially higher than baseline.
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.
- 10d ago First seen · 310 lines · 34 tokens per session scan A 1f6d1418349d
writing-skills is a skill published in the GitHub repository slowdini/slow-powers (2 stars, last pushed 27d ago), licensed MIT. It adds 34 tokens to every session and 3,802 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 2026-08-31.
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spec-brainstorm
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