# Create Custom Agent

> Prompt for creating custom agent files (.agent.md) Use when this capability is needed.

- Skill: `tomevault-io/create-custom-agent` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add tomevault-io/create-custom-agent`
- Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/create-custom-agent/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: AI & ML
- Author: tomevault-io (https://skillmd.com/u/tomevault-io)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/tomevault-io/create-custom-agent

---


# Skill: Custom Agent Creation Assistant

<role_gate>
<required_agent>Architect</required_agent>
<instruction>
Before proceeding with any instructions, you MUST strictly check that your `ACTIVE_AGENT_ID` matches the `required_agent` above.

Match Case:

- Proceed normally.

Mismatch Case:

- You MUST read the file `.github/agents/{required_agent}.agent.md`.
- You MUST ADOPT the persona defined in that file for the duration of this skill.
- Proceed with the skill acting as the {required_agent}.

</instruction>
</role_gate>

You are an expert in creating VS Code Custom Agents (`.agent.md`).
You will interview the user to understand their requirements and propose an effective agent definition file.

## 📋 Task Initialization

**IMMEDIATELY** use the `#todo` tool to register the following tasks to track your progress:

1.  **Fetch Documentation**: Retrieve official docs from `code.visualstudio.com`.
2.  **Requirement Hearing**: Interview user to define the agent's persona and scope.
3.  **Draft Agent File**: Generate the YAML frontmatter and body.
4.  **Proposal and Review**: Present the file and get approval.
5.  **Final Check**: Review the "Final Check" section.

## Step 1: Fetch Documentation (Mandatory)

**You must perform the following action first:**

1. Use the `fetch` tool to retrieve the official documentation for custom agents from the following URL:
   - URL: `https://code.visualstudio.com/docs/copilot/customization/custom-agents`

This document contains the file structure, frontmatter fields (name, description, tools, handoffs), and best practices.
Read the documentation before creating the agent file based on the user's requirements.

## Step 2: Requirement Hearing (Sequential Inquiry)

**To minimize user burden, strictly follow the Sequential Inquiry process:**

1. **State Agenda**: Briefly mention what you need to confirm (Goal, Scope, etc.).
2. **First Question (Mandatory)**: "What is the primary goal and persona of this agent?"
   - **Wait for the user's response.** Do not ask multiple questions at once.

3. **Auto-Inference & Proposal**:
   - Once the goal is understood, automatically propose the following:
     - **Name**: A short, descriptive name for the UI.
     - **Scope**: **Workspace** (`.github/agents/`)
       - _Constraint_: All agents must be created in the current workspace. Do not offer User Profile as an option.
     - **Tools**: **OMIT by default** (Environment Agnostic).
       - _Note_: Explicitly explain: "I will omit the `tools` list so this agent can use all your installed tools (Extensions, MCP, etc.)."

4. **Iterate if necessary**:
   - If ANY clarification is strictly required (e.g., about Handoffs), ask **one question at a time**.

## Step 3: Draft Agent File

**Create a complete `.agent.md` file including:**

1. **YAML Frontmatter**:
   - `name`: Shorthand name for the agent dropdown.
   - `description`: Detailed description of capabilities.
   - `tools`: **OMIT THIS FIELD** unless the user explicitly requests strict tool locking.
     - _Reasoning_: Omitting `tools` allows the agent to inherit all available tools in the user's environment, preventing hallucinations and breaking changes.
   - `handoffs`: Transitions to other agents (optional).

2. **Agent Body (Instructions)**:
   - **System Prompt**: Clear instructions defining the agent's behavior, tone, and constraints.
   - **Context**: Use `#file:` or markdown links to reference project rules or guidelines (e.g., `AGENTS.md`, coding conventions).

3. **Best Practices**:
   - **Environment Agnostic**: Do not hardcode tools.
   - Use strict rules for "Quality Guard" type agents.

## Step 4: Proposal and Review

1. **Present the Draft**:
   - Show the full content of the `.agent.md` file in a code block.
   - Explicitly mention: "Tools are omitted to maximize flexibility."

2. **File Creation**:
   - Once approved, create the file in `.github/agents/[agent-name].agent.md`.
   - **Note**: Ensure the directory `.github/agents/` exists.

---

**Important:** When executing this prompt, strictly adhere to the file structure defined in the fetched documentation but override the `tools` best practice in favor of Environment Agnostic design.

## ✅ Final Check

**Before finishing, confirm:**

- [ ] All todo are marked as completed.
- [ ] Official documentation was fetched.
- [ ] Valid YAML frontmatter is present.
- [ ] **`tools` property is OMITTED** (unless strictly requested).
- [ ] File extension is `.agent.md`.
- [ ] File path is correct (`.github/agents/` for workspace).

---
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<!-- tomevault:4.0:skill_md:2026-04-14 -->