Step 2 — interview to fill. Ask one question per missing field, in this order:
- What it does — one sentence, primary triggering signal.
- When to invoke — common task framings the user would say. Combined
description + when_to_use is capped at 1,536 chars per the Anthropic spec.
- Tools needed —
Read, Write, Glob, Grep, Bash, Task, ... Restrict to what the skill actually uses.
- Body shape — instructions, optional template, output contract. Keep ≤500 lines; move long material to sibling files (
reference.md, examples.md, scripts/).
Do NOT invent values. When the user does not know something, ask. Do NOT invent fields not in the spec — only declare frontmatter fields that actually apply.
Step 3 — write the file(s).
Path:
- Claude Code project:
.claude/skills/<name>/SKILL.md
- Claude Code personal:
~/.claude/skills/<name>/SKILL.md
- Codex project:
.agents/skills/<name>/SKILL.md plus .agents/skills/<name>/agents/openai.yaml (cc-sdd convention).
Frontmatter per agent:
- Claude Code:
name, description, allowed-tools (and any other field from the spec the user asked for).
- Codex: minimal frontmatter —
name, description. Body uses XML tags (<background_information>, <instructions>, <template>, <output_contract>). The agents/openai.yaml carries interface.display_name, interface.short_description, policy.allow_implicit_invocation.
Body: imperative instructions ("do X", not "this skill does X"). Every line is recurring token cost once the skill loads — be terse. Don't restate AGENTS.md.
Step 4 — stop after writing. Do not invoke the new skill, do not pre-fill it with example content, do not test it. The user will exercise it themselves.
Next
- Test the new skill's description triggers by invoking it from a real conversation — verify auto-triggering on the keywords you chose.
- If the skill is meant to be universal across the kit's profiles, propose an ADR + Task to add it to the profile catalog (
src/lib/profiles.js).
- If the skill carries a sibling subagent, declare it in
manifest.json and add the source under agents/.
Source: alexandremendoncaalvaro/agentic-development — distributed by TomeVault.
1---2name: ad-skill3description: Draft a new Claude Code or Codex skill at .claude/skills/<name>/SKILL.md (or .agents/skills/<name>/SKILL.md for Codex), using the Anthropic Skills format. Use when the user wants to create, write, draft, or scaffold a custom skill for an agentic coding tool. Asks one question per missing field; never invents skill names or triggers. Use when this capability is needed.4---56<background_information>7Drafts `.claude/skills/<name>/SKILL.md` (Claude Code) or `.agents/skills/<name>/SKILL.md` plus `agents/openai.yaml` (Codex). Spec: code.claude.com/docs/en/skills. Open standard: agentskills.io. Examples: github.com/anthropics/skills.8</background_information>910<instructions>11Step 1 — confirm target. Ask the user:12- Name — kebab-case, lowercase, ≤64 chars. Becomes the directory name and the slash command.13- Target agent(s) — Claude Code, Codex, or both. Determines path and frontmatter shape.14- Personal or project — `~/.claude/skills/<name>/` (personal) vs `.claude/skills/<name>/` (project, committed). Default: project.1516Step 2 — interview to fill. Ask one question per missing field, in this order:17- What it does — one sentence, primary triggering signal.18- When to invoke — common task framings the user would say. Combined `description` + `when_to_use` is capped at 1,536 chars per the Anthropic spec.19- Tools needed — `Read, Write, Glob, Grep, Bash, Task, ...` Restrict to what the skill actually uses.20- Body shape — instructions, optional template, output contract. Keep ≤500 lines; move long material to sibling files (`reference.md`, `examples.md`, `scripts/`).2122Do NOT invent values. When the user does not know something, ask. Do NOT invent fields not in the spec — only declare frontmatter fields that actually apply.2324Step 3 — write the file(s).2526Path:27- Claude Code project: `.claude/skills/<name>/SKILL.md`28- Claude Code personal: `~/.claude/skills/<name>/SKILL.md`29- Codex project: `.agents/skills/<name>/SKILL.md` plus `.agents/skills/<name>/agents/openai.yaml` (cc-sdd convention).3031Frontmatter per agent:32- Claude Code: `name`, `description`, `allowed-tools` (and any other field from the spec the user asked for).33- Codex: minimal frontmatter — `name`, `description`. Body uses XML tags (`<background_information>`, `<instructions>`, `<template>`, `<output_contract>`). The `agents/openai.yaml` carries `interface.display_name`, `interface.short_description`, `policy.allow_implicit_invocation`.3435Body: imperative instructions ("do X", not "this skill does X"). Every line is recurring token cost once the skill loads — be terse. Don't restate AGENTS.md.3637Step 4 — stop after writing. Do not invoke the new skill, do not pre-fill it with example content, do not test it. The user will exercise it themselves.38</instructions>3940<output_contract>41A single new `SKILL.md` at the chosen path (plus `agents/openai.yaml` for Codex). Frontmatter declares only the fields actually used. Body is imperative and terse. No external file dependencies the user did not ask for.42</output_contract>4344## Next4546- Test the new skill's description triggers by invoking it from a real conversation — verify auto-triggering on the keywords you chose.47- If the skill is meant to be universal across the kit's profiles, propose an ADR + Task to add it to the profile catalog (`src/lib/profiles.js`).48- If the skill carries a sibling subagent, declare it in `manifest.json` and add the source under `agents/`.4950---51> Source: [alexandremendoncaalvaro/agentic-development](https://github.com/alexandremendoncaalvaro/agentic-development) — distributed by [TomeVault](https://tomevault.io).52<!-- tomevault:4.0:skill_md:2026-06-16 -->
