--- title: "Quickstart" description: "Create your first Agent Skill and see it work in VS Code." --- In this tutorial, you'll create a skill that gives an agent the capability to roll dice using a random number generator. ## Prerequisites - [VS Code](https://code.visualstudio.com/) with [GitHub Copilot](https://marketplace.visualstudio.com/items?itemName=GitHub.copilot) This tutorial uses VS Code, but Agent Skills are an open format. The same skill works in any compatible agent, including Claude Code and OpenAI Codex. ## Create the skill A skill is a folder containing a `SKILL.md` file. VS Code looks for skills in `.agents/skills/` by default. Create `.agents/skills/roll-dice/SKILL.md` in your project: ````markdown .agents/skills/roll-dice/SKILL.md --- name: roll-dice description: Roll dice using a random number generator. Use when asked to roll a die (d6, d20, etc.), roll dice, or generate a random dice roll. --- To roll a die, use the following command that generates a random number from 1 to the given number of sides: ```bash echo $((RANDOM % + 1)) ``` ```powershell Get-Random -Minimum 1 -Maximum ( + 1) ``` Replace `` with the number of sides on the die (e.g., 6 for a standard die, 20 for a d20). ```` That's it — one file, under 20 lines. Here's what each part does: - **`name`** — A short identifier for the skill. Must match the folder name. - **`description`** — Tells the agent when to use this skill. This is how the agent decides whether to activate it. - **The body** — Instructions the agent follows when the skill activates. Here, the agent is instructed to generate a random number using a terminal command, substituting the number of sides from the user's request. ## Try it out 1. Open your project in VS Code. 2. Open the Copilot Chat panel. 3. Select **Agent** mode from the mode dropdown at the bottom of the chat panel. 4. Type `/skills` to confirm that `roll-dice` appears in the list. If it doesn't, check that the file is at `.agents/skills/roll-dice/SKILL.md` relative to your project root. 5. Ask: **"Roll a d20"** The agent should activate the `roll-dice` skill. It may ask for permission to run a terminal command — allow it. It will run the command and return a random number between 1 and 20. Tool-use reliability varies across models — some follow skill instructions and run commands consistently, while others may attempt to answer on their own. If the agent responds without running a terminal command, try selecting a different model from the model dropdown. ## How it works Here's what happened behind the scenes: 1. **Discovery** — When the chat session started, the agent scanned default skill directories and found your skill. It read only the `name` and `description`, just enough to know when the skill might be relevant. 2. **Activation** — When you asked about rolling dice, the agent matched your question to the skill's description and loaded the full `SKILL.md` body into context. 3. **Execution** — The agent followed the instructions in the body, adapting the terminal command to the number of sides in your request. This process uses **progressive disclosure** to let the agent access many skills without loading all their instructions up front. For more detail, see [How skills work](/what-are-skills#how-skills-work). ## Next steps You've created a working Agent Skill. From here: - **[Best practices](/skill-creation/best-practices)** — How to write skills that are well-scoped and effective. - **[Optimizing skill descriptions](/skill-creation/optimizing-descriptions)** — Test and improve your skill's description so it activates on the right prompts. - **[Specification](/specification)** — The complete format reference for `SKILL.md` files. - **[Example skills](https://github.com/anthropics/skills)** — Browse real-world skills on GitHub.