# Skill Builder > | - **Type:** Skill - **Install:** `agentstack add skill-samuelbostic29-claude-skills-skill-builder` - **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior - **Seller:** [SamuelBostic29](https://agentstack.voostack.com/s/samuelbostic29) - **Installs:** 0 - **Category:** [AI & ML](https://agentstack.voostack.com/c/ai-and-ml) - **Latest version:** 0.1.0 - **License:** MIT - **Upstream author:** [SamuelBostic29](https://github.com/SamuelBostic29) - **Source:** https://github.com/SamuelBostic29/claude-skills/tree/main/skills/skill-builder ## Install ```sh agentstack add skill-samuelbostic29-claude-skills-skill-builder ``` Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent. ## About # Skill Builder: turn a one-line brief into a review-ready skill You are turning a brief problem statement into a finished, review-ready skill. Your job is to do the research, scope the skill to a **single job**, fill every layer of the template, scaffold its evals, then **STOP for review**. You never install, commit, or push what you scaffold. The failure mode this skill exists to prevent is the **kitchen-sink skill**: a vague brief becomes a skill that tries to do three things, leads with "helps with" filler, lists every tool, and ships with half its `` placeholders unfilled. Guard against it on every build — one job, trigger-first description, minimal tools, zero surviving placeholders. ## When to use this skill - "Build / create / scaffold a skill for X" - Someone describes a recurring task — usually with a repo or an example — and wants it turned into a reusable skill - Turning a skill brief or issue (like this repo's issues) into an actual `skills//` folder ## When NOT to use this skill - **Editing or reviewing an existing skill** — open it and edit it directly; this skill authors new ones. - **The "skill" is really a one-off** — a single shell command, a config tweak, or a permission rule. Not every task needs a skill; say so and stop. (Settings or hook changes are a config task, not a skill.) - **The brief implies several unrelated jobs** — that's N skills, not one. This skill builds one at a time; propose the split (step 5). ## Steps 1. **Intake.** Capture the brief problem, any context (repo path, an example, the specific pain point), and the target output mode. Default to **portable** unless a real repo is in play and the user wants the skill baked for it — then **project** (see Rules → Output modes). 2. **Read the anatomy.** Read `references/skill-anatomy.md` for the exact structure and quality bar you must produce. If `template/` exists in the working repo, that folder is your canonical starting scaffold (`cp -r template skills/`); otherwise reproduce the same structure from the reference. 3. **Clarify — as much as it takes, no padding.** Ask via AskUserQuestion until you genuinely understand the single job, its triggers, the target output mode, and the key decisions the skill must encode. A thin brief may need several rounds to become a valuable, detailed skill; a detailed brief may need none. Batch related questions (up to 4 per prompt) instead of drip-feeding, ask only what you can't settle yourself by researching the repo (step 4) or by a sensible stated default, and stop once another answer wouldn't change the scaffold — depth where it makes the skill better, never interrogation for its own sake. **Never guess the skill's purpose** — that is the one thing you may not invent. 4. **Research.** If pointed at a repo, explore it with Read / Grep / Glob — README, any existing `.claude/skills/`, naming and code conventions, domain vocabulary, how it runs tools — so the new skill is grounded and doesn't reinvent patterns the repo already has. 5. **Scope to one job.** Distill the brief to a single crisp purpose. If it implies multiple jobs, **propose splitting into N named skills and confirm which to build first** — then build only that one. Do not scaffold until the scope is one job. 6. **Scaffold.** Create the skill folder — `skills//` (portable) or the target repo's `.claude/skills//` (project) — and fill **every** placeholder: kebab `name` matching the folder, trigger-first `description`, **minimal** `allowed-tools` inferred from the job, When to use / When NOT to use, numbered Steps with explicit stop conditions, Output format, and the Rules triad. 7. **Layer 3 + evals.** Add a `references/` file only if the skill needs a big catalog, signature table, or worked examples; otherwise omit it. **Always** write `evals/README.md` with 2–3 representative cases, including at least one **negative** "should not fire / should ask instead" case. 8. **Self-check.** Verify against the checklist in `references/skill-anatomy.md`: no surviving `` (portable mode), `name` matches the folder, description leads with the trigger, `allowed-tools` is minimal, output is portable unless project mode was chosen. Fix anything that fails before reporting. 9. **Report & stop.** Print the new skill's path, a one-paragraph summary (the job and its triggers), and the evals to run. Do **not** install, commit, or push. Stop. ## Output format Report exactly this, then stop: ``` Created skill: /SKILL.md (mode: portable | project) Job: Triggers: Files: SKILL.md, evals/README.md[, references/] Verify with: Not done for you: not installed, not committed. To try it: cp -r ~/.claude/skills/ and run the evals in a fresh session. ``` ## Rules ### What to do - **One job, always.** A skill has a single purpose. If you need "and" to describe it, it is two skills — propose the split and build one. - **Trigger-first description.** Lead the `description` with a tight statement of the job, with the trigger words a user would actually say ("build / create / scaffold a skill") right up front — it is the only layer-1 metadata and it decides whether the skill triggers at all. - **Minimal `allowed-tools`.** List only the tools the job needs. A read-only skill lists no `Write`/`Edit`/`Bash`. Infer the set from the steps, not from habit; scope `Bash` to subcommands when you can (e.g. `Bash(git status:*)`). - **Ask until the job is clear — by sufficiency, not a quota.** Ask as many genuine questions as it takes to scope a valuable, detailed skill; ask none if the brief already settles it. No padding, batch related ones, and never ask what you could answer by researching the repo. Ask, don't guess. - **Ship evals.** Every skill gets 2–3 cases and at least one negative case — a skill without a way to prove it works is unfinished. ### What NOT to do - **NEVER ship a kitchen-sink skill.** Multi-job briefs get split, not crammed. - **NEVER leave a surviving ``** in portable output. The self-check exists to catch this. - **NEVER guess the skill's purpose.** Ask, or stop — purpose is the one thing you may not invent. - **NEVER install, commit, or push** the scaffold. The deliverable is files for review; landing them is the user's call. - **Don't manufacture a skill for a one-off.** A single command or config change isn't a skill — say so and stop. ### Output modes - **Portable (default).** Placeholders, no org names, no real paths, no stack or schema assumptions — the kind of skill that ships in this repo. Everything project-specific is an `` the adopter fills in. - **Project.** Only when pointed at a real repo and explicitly asked: bake that repo's real paths and conventions into a skill destined for its local `.claude/skills/`. The skill *itself* stays portable — the mode governs only the *output*. ### Format discipline - The deliverable is the files plus a tight report. No preamble, no narrating the research, no recap. Scaffold, report, stop. For the full structure, quality bar, and finished-skill checklist, read `references/skill-anatomy.md`. ## Source & license This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code. - **Author:** [SamuelBostic29](https://github.com/SamuelBostic29) - **Source:** [SamuelBostic29/claude-skills](https://github.com/SamuelBostic29/claude-skills) - **License:** MIT Install and usage instructions live in the source repository linked above. ## Pricing - **Free** — Free ## Security capabilities Automated source analysis of v0.1.0 — what this tool can access: - **Network access:** no - **Filesystem access:** no - **Shell / process execution:** no - **Environment & secrets:** no - **Dynamic code execution:** no *"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.* ## Versions - **0.1.0** — security scan: passed — Imported from the upstream source. ## Links - Listing page: https://agentstack.voostack.com/l/skill-samuelbostic29-claude-skills-skill-builder - Seller: https://agentstack.voostack.com/s/samuelbostic29 - Browse the marketplace: https://agentstack.voostack.com/browse --- Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.