# Creating Agents And Skills > Use when the user wants to create, add, extend, or modify an agent, skill, or workflow in this kit (e.g. "create a skill for our dbt naming standard", "add an agent for X", "new workflow"). Decides whether to build an agent, a skill, or nothing, enforces lean quality standards, and keeps every installed AI-tool folder (.agent, .claude, .github, .opencode, AGENTS.md) identical in each tool's nativ… - **Type:** Skill - **Install:** `agentstack add skill-luccapinto-agentic-data-kit-creating-agents-and-skills` - **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior - **Seller:** [luccapinto](https://agentstack.voostack.com/s/luccapinto) - **Installs:** 0 - **Category:** [Developer Tools](https://agentstack.voostack.com/c/developer-tools) - **Latest version:** 0.1.0 - **License:** MIT - **Upstream author:** [luccapinto](https://github.com/luccapinto) - **Source:** https://github.com/luccapinto/agentic-data-kit/tree/main/.opencode/skills/creating-agents-and-skills ## Install ```sh agentstack add skill-luccapinto-agentic-data-kit-creating-agents-and-skills ``` Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent. ## About # Skill: creating-agents-and-skills The governance gate for extending this kit. Goal: people add capabilities **only when they help**, build them **with quality**, and every installed tool folder stays **in sync**. Follow three phases in order: **Decide → Author → Propagate.** --- ## Phase 1 — Decide what (if anything) to build Run these gates before creating anything. If a gate says stop, explain why and stop. - **LLM-native? → don't create.** If a capable model already does this well ("write clean code", "use CTEs", "explain this function"), no artifact is needed. Just do the task. - **Narrow knowledge / a tool / a format / a checklist? → make a SKILL.** Most additions are skills: a team naming standard, a framework's rules, a validation procedure. Skills auto-activate by description and cost almost nothing until used. - **A distinct role with its own domain and judgement? → make an AGENT.** Only when there's a persona that owns a body of work (like `data-engineer`). Agents are expensive (routing, attention); the bar is high. - **Overlaps an existing agent/skill? → extend it,** don't add a near-duplicate. Ambiguous routing between two similar artifacts degrades results. - **A repeatable multi-step procedure the user invokes? → make a WORKFLOW** (slash command). > Default to a skill. Recommend an agent only if you can name the distinct domain it owns and > confirm nothing existing covers it. --- ## Phase 2 — Author it lean Write only domain/org-specific signal. No filler, no restating what the model knows. English. **Agent** — `.agent/agents/.md`: ```yaml --- name: description: One sharp sentence on what it does + trigger keywords (drives routing). tools: Read, Grep, Glob, Bash, Edit, Write model: inherit skills: skill-a, skill-b # optional hints; skills also self-activate --- # → domain rules → handoffs to other agents → out-of-scope. ``` **Skill** — `.agent/skills//SKILL.md` (gerund-style name, e.g. `validating-dbt-models`): ```yaml --- name: description: What it does AND when to use it, in the third person, with trigger words so it auto-activates (e.g. "Use when the user asks to ... "). This is the most important field. --- # Skill: → concrete rules or steps. Keep the body under ~500 lines; move long reference material to sibling files (e.g. reference.md, scripts/) and link them. ``` Write descriptions in the **third person** ("Generates...", "Use when...") — never "I can help". The description is what makes the skill fire without the user naming it. **Workflow** — `.agent/workflows/.md`: `description` frontmatter + concise numbered steps. --- ## Phase 3 — Propagate to every installed tool folder A capability must exist, identically, in each AI tool the project uses — each in its native format. Pick the path that matches the project: ### Path A — Source of truth present (`.agent/` + `scripts/sync_agents.py` exist) This is the kit repo or an Antigravity install. **Author in `.agent/` only, then sync:** ```bash python scripts/sync_agents.py ``` The script regenerates `.claude/`, `.github/`, `.opencode/`, `.cursor/`, and root `AGENTS.md` (which also covers OpenAI Codex). Never hand-edit those — they're overwritten. Done. ### Path B — No source of truth (user installed one or more tool flavors) Detect which folders exist and write the artifact into **each present folder** in its native format (the body content stays identical; only frontmatter changes). Format mapping: | Concept | `.agent` (Antigravity) | `.claude` (Claude Code) | `.github` (Copilot) | `.opencode` (OpenCode) | `.cursor` (Cursor) | |---|---|---|---|---|---| | Agent | `agents/.md` | `agents/.md` (identical) | `agents/.agent.md` — frontmatter `name`, `description` only (no `tools`) | `agents/.md` — frontmatter `description`, `mode: subagent`, `permission` (drop `tools`/`model`/`name`/`skills`) | — (Cursor has no file-based agents) | | Skill | `skills//SKILL.md` | `skills//SKILL.md` (identical) | `skills//SKILL.md` (identical) | `skills//SKILL.md` (identical) | — (no skills concept) | | Workflow | `workflows/.md` | `commands/.md` (native slash command) + `workflows/.md` | `prompts/.prompt.md` — frontmatter `name`, `description`; body starts `**Context:** ${selection}` | `commands/.md` (identical) | `commands/.md` (identical) | | Global rule | `rules/rules.md` (with `trigger: always_on`) | `CLAUDE.md` (rules + commands section) | `copilot-instructions.md` (rules) | root `AGENTS.md` (rules) | `rules/.mdc` — frontmatter `description`, `globs`, `alwaysApply: true` | Rules: - **Strip the `trigger: always_on` frontmatter** from `rules.md` when writing it anywhere outside `.agent/` — it's Antigravity-only and is noise everywhere else. - **OpenCode reads the root `AGENTS.md`**, not `.opencode/AGENTS.md` — don't create the latter. The same root `AGENTS.md` is what **OpenAI Codex** reads, so Codex needs no dedicated folder. - Frontmatter differs per tool (Copilot agent/prompt, OpenCode agent, Cursor rule/mdc); the **body is a verbatim copy** everywhere. - Create the same `` in all present folders — do not leave a tool behind. - If the user installed only one folder but wants multi-tool support, offer to add the others. ### Verify parity After either path, confirm the artifact exists in every present tool folder and that no folder references something that no longer exists. State which folders you wrote. --- ## Anti-patterns - Creating an agent for a single tool or task (e.g. "GitAgent"). Tools don't need agents. - Putting episodic guidance in the always-on rules — it belongs in a skill like this one. - Editing generated folders (`.claude`/`.github`/`.opencode`/`.cursor`/`AGENTS.md`) when `.agent/` exists. ## Source & license This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code. - **Author:** [luccapinto](https://github.com/luccapinto) - **Source:** [luccapinto/agentic-data-kit](https://github.com/luccapinto/agentic-data-kit) - **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-luccapinto-agentic-data-kit-creating-agents-and-skills - Seller: https://agentstack.voostack.com/s/luccapinto - 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%.