/book-to-skill

name: book-to-skill
description: 'Use when turning a book, course, whitepaper, or comparable source document into a reusable agent skill: the user names a source and asks to distill it, encode its method, or build an agent that works the way it prescribes. Classifies the source as procedure or reference, writes a validated SKILL.md, and proves the trigger fires before finishing.'
argument-hint: "Which book or document should become a skill?"

Turn a source document into a skill the agent can run. Nine steps, each with a done condition. The source is a single book, course, paper, or comparable document; a folder of sources belongs to `map-corpus`, not here.

1. Read the source

Inventory the source at the level the document affords: chapters, top-level headings, or sections. Show that inventory as one line per unit with its heading slug where one exists. A file the agent cannot open stops the run and is named; this skill owns no converter either. Done when the inventory covering every top-level unit is shown.

2. Classify

Ask: can you name three or more ordered actions, each with a checkable done-state? Three or more, **procedure** (a sequence the agent can follow). Fewer, **reference** (distinctions and rules consulted on demand). Both present, a procedure spine with the judgment material in `references/`. Done when the classification is stated with the three actions named, or with the statement that fewer than three exist.

3. Extract into four buckets

Sort what you read: coined terms and leading words, constraints and prohibitions, procedures with their completion criteria, and deep material destined for `references/`. Done when every inventoried unit has contributed to a bucket or is marked as out of scope for the skill.

4. Name it

Kebab-case matching `^[a-z0-9]+(-[a-z0-9]+)*$`, at most 64 characters, identical to the directory name. Done when the name matches the directory you will write to.

5. Write the frontmatter

`description` at most 1024 characters, front-loaded, one trigger per genuinely distinct branch, phrased positively. Redirect rather than forbid: "for X, use skill Z" rather than "do not use for X". Done when the `description` parses as single-quoted YAML and is within the limit.

6. Write the body

Write the body in the shape its classification selects, from [references/OUTPUT-SHAPES.md](references/OUTPUT-SHAPES.md). Include one attribution line naming title, author, and year. Paraphrase throughout; quote only a coined term or named law where the exact phrasing is the idea. Done when the body follows its shape and carries the attribution.

7. Disclose

Material only some branches reach moves to `references/<topic>.md`, linked one level deep from the body. Keep the body under 500 lines. Done when branch-specific material lives behind a pointer and the body line count is under the cap.

8. Validate

Check four conditions: `name` equals the directory name; the frontmatter parses as YAML; `description` is within 1024 characters; every relative link resolves on disk. Run `yaml.safe_load` on the frontmatter and `test -f` on each link target. Done when all four pass.

9. Probe and place

Author three to five probe prompts — at least two that must fire the skill, at least two out-of-scope prompts that must not — and run each in a subagent. Adjust the `description` until every probe lands correctly. Then ask for the write target, defaulting to `.claude/skills/<name>/`, and re-run step 8 there. Done when probe results are reported and the checks are green at the target.

Rules

• One skill per run. Another source is another run.
• Paraphrase the source; do not paste it.
• Keep the skill runnable without the source in context. The skill, not the book, is the source of truth when the skill runs.