craft-skilllisted

# Skill: Craft Skill > "Atomic units of intelligence." ## The Principles - **Atomicity**: One concept per file. If it does two things, split it. - **Brevity**: Less is more. No verbose explanations. - **Expertise**: Write *how an expert thinks*, not checklists. - **Eighty lines, and it is ours**: front matter and all. Anthropic's published ceiling is 500, for performance. Eighty is stricter and answers two questions it does not. A skill is read into attention whole, so its length is what crowds out the next one — **and a person has to read it too.** Eighty is a screen. Past it, a skill is two skills. - **Atomic examples**: one subject per file, named for it. Anthropic calls this **progressive disclosure**, and adds the rule that matters — **references stay one level deep from `SKILL.md`**, so a file it sends you to is read whole rather than chased. - **A description is read at 250 characters**: 1,024 is the hard limit, but only the first 250 reach the listing Claude picks from. A trigger word past 250 is invisible. ## Choose a Template | Template | Use When | Pattern | |-----------------------------------------------------|---------------------|----------------------------------------| | [decide](templates/decide.md) | X vs Y decision | Heuristic + Quick Test + examples.md | | [craft](templates/craft.md) | How to build X