Agent Frontmatter

ValidatorAgentsOfficial docsSubagent frontmatter fields

Agent files are flat .md files (e.g., .claude/agents/code-reviewer.md). The YAML frontmatter configures the agent; the file body is the system prompt.

Fields

Field	Type	Required	Description
name	string	yes	Lowercase with hyphens, max 64 chars
description	string	yes	Min 10 chars, third-person voice
model	string	no	sonnet, opus, haiku, or inherit (valid values)
tools	string[]	no	Tool names to allow
disallowedTools	string[]	no	Tool names to disallow
permissionMode	string	no	default, acceptEdits, dontAsk, bypassPermissions, plan, or delegate
skills	string[]	no	Skills this agent can use
hooks	object	no	Hooks configuration
memory	string	no	user, project, or local
maxTurns	number	no	Maximum agent turns (positive integer)
mcpServers	string[]	no	MCP servers available to the agent
color	string	no	blue, cyan, green, yellow, magenta, red, or pink

Cross-field validations:

• tools and disallowedTools are mutually exclusive

Example

---
name: code-reviewer
description: Reviews code changes for quality, security, and best practices.
model: sonnet
tools:
  - Read
  - Glob
  - Grep
color: blue
---