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 Conradgui/matt-pocock-inspired-skill-writing --skill skill-writing-guidelinesgit clone --depth 1 https://github.com/Conradgui/matt-pocock-inspired-skill-writingWrote 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/conradgui/matt-pocock-inspired-skill-writing/skill-writing-guidelines)<a href="https://agentmods.dev/skills/conradgui/matt-pocock-inspired-skill-writing/skill-writing-guidelines"><img src="https://agentmods.dev/badge/skills/conradgui/matt-pocock-inspired-skill-writing/skill-writing-guidelines/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/conradgui/matt-pocock-inspired-skill-writing/skill-writing-guidelines"><img src="https://agentmods.dev/badge/skills/conradgui/matt-pocock-inspired-skill-writing/skill-writing-guidelines.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 | $0.00038 | $0.00910 |
| Opus 5 | $0.00019 | $0.00455 |
| Sonnet 5 | $0.00008 | $0.00182 |
| Haiku 4.5 | $0.00004 | $0.00091 |
Grade A, and why
skill-writing-guidelines 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 11d 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 — 91 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Skill Writing Guidelines
Make the skill's process predictable across runs, without requiring identical outputs. Apply the active agent platform's native fields and validators; translate patterns from other harnesses instead of copying their metadata unchanged.
1. Establish the behavior contract
Use concrete runs to identify the outcome, trigger branches, near misses, inputs and state, side effects, success evidence, and failure behavior. Inspect existing callers and artifacts before changing an existing skill. Treat a user-reported symptom as high-value evidence and the proposed cause as a hypothesis to verify against files, history, tests, traces, and callers.
Done when: every genuine branch has a concrete example and an observable success or failure condition.
2. Assign responsibility
Keep reusable discipline and vocabulary in primitives, end-to-end sequencing in orchestrators, cross-session facts in narrow artifacts, platform commands behind adapters, and human discovery in a router. Give each responsibility one owner.
Done when: every proposed skill has one coherent contract and shared behavior has one source of truth.
3. Design invocation and hierarchy
Treat a model-facing description as a branch index: front-load the core action and add one trigger per genuine branch. Inline what every run needs. Move branch-only reference behind a pointer that says when and why to read it. Use leading words to compress behavior only when they are precise.
Done when: invocation mode is deliberate, every conditional resource has a firing condition, and the main path is legible without irrelevant branches.
4. Encode gates and state
Validate cheap shared preconditions before expensive work. End consequential steps with observable, exhaustive criteria. Separate discoverable facts from user decisions, and persist cross-session state in purpose-built artifacts. Isolate independent evaluation axes when one can bias another.
Done when: another agent can follow every branch without inventing the source order, authority, stopping rule, or evidence standard.
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.
- 11d ago First seen · 91 lines · 38 tokens per session scan A 9da0c1c91c5a
skill-writing-guidelines is a skill published in the GitHub repository Conradgui/matt-pocock-inspired-skill-writing (7 stars, last pushed 1mo ago), licensed MIT. It adds 38 tokens to every session and 910 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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