pm-claude-skills/SKILL-AUTHORING-STANDARD.md

Skill Authoring Standard

This is the canonical structure every skill in this library follows. It exists so that 160+ skills feel like one coherent product rather than a folder of loose prompts, and so contributors know exactly what "done" looks like. If you are adding or editing a skill, match this standard.

It complements CONTRIBUTING.md (how to submit) — this document is about what a good skill contains.

---

1. File layout

skills/
  your-skill-name/
    SKILL.md            # required — the skill itself
    scripts/            # optional — stdlib-only helper programs
      your_helper.py

• One skill per folder. Folder name = skill name = name in the frontmatter.
• Use lowercase, hyphenated names (customer-journey-map, not CustomerJourneyMap).
• A skill must be useful with SKILL.md alone. Scripts are an enhancement, never a prerequisite.
• Never hand-edit exports/. Those platform files (e.g. ChatGPT SYSTEM_PROMPT.md) are generated from the SKILL.md body by scripts/build-exports.mjs. Edit the source skill and regenerate; CI fails if they drift.

2. Frontmatter (required)

---
name: your-skill-name
description: "One sentence on what it does. Use when [trigger conditions]. Produces [the concrete output]."
---

The description is the single most important line — it is all the model sees when deciding whether to load the skill. It must contain three things:

1. What the skill does, in one clause.
2. Use when… — explicit trigger phrases a user would actually say.
3. Produces… — the concrete artifact, so the model knows the payoff.

Keep it under ~3 sentences. Write triggers from the user's vocabulary, not internal jargon.

3. Body sections

Use this section order. Not every skill needs every section, but strong skills include most of them, and the bold ones are required.

Section	Purpose
# Skill Title + one-line summary	Required. Restate the value in plain language.
What This Skill Produces	Bullet list of the deliverables. Sets expectations.
Required Inputs	What to ask the user for if it isn't provided. Prevents guessing.
Framework / Formula / Scale	The method, rubric, weights, or formula the skill applies.
Programmatic Helper	If the skill has a script, show how to run it and what it returns.
Output Format	A concrete template (headings, tables) of the final artifact.
Quality Checks	A checklist the output must pass before it's handed over.
Anti-Patterns	Explicit "Do not…" rules — the mistakes this skill prevents.

4. Quality bar

A skill is ready to merge when:

• The description has all three parts (what / use when / produces).
• It solves a recurring professional workflow, not a one-off task.
• It asks for missing inputs rather than inventing them.
• The output format is concrete enough that two runs look like the same product.
• It includes Quality Checks and Anti-Patterns — these are what make a skill trustworthy, not just a prompt.
• It works with no setup beyond reading the file (scripts excepted, and those are stdlib-only).

5. Helper scripts (optional)

Some skills ship a scripts/ folder that computes part of the work. Rules:

• Standard library only. No pip install. No third-party imports.
• No network access, no surprise file writes. Read input, print output.
• Accept input via flags and JSON (file or stdin); offer --json output for chaining.
• Include a module docstring with runnable examples and a --help via argparse.
• The script augments the skill — the SKILL.md must still produce a good result without it.

See skills/rice-prioritisation/scripts/rice_calculator.py for a reference example.

6. Tone and safety

• Write instructions to the model ("Ask for…", "Flag any…", "Never write…").
• British or American spelling is fine; be consistent within a skill.
• No prompt injection, no instructions to override model guidelines, no requests to collect or transmit user data. See SECURITY.md.

7. Tiering

New skills enter as Experimental. Once a skill has a stable output format, quality checks, and real-world use, it can be promoted to Stable or Production-Ready in TIERS.md. Tiering is honest signposting, not a value judgement on effort.