custom-agent-definitions

# Custom Agent Definitions Expert knowledge for defining and configuring custom agents in Claude Code. For full worked YAML examples (isolated research agent, read-only explorer, complete security auditor, plugin layout, common patterns), see [REFERENCE.md](REFERENCE.md). ## When to Use This Skill | Use this skill when... | Use agent-teams instead when... | |---|---| | Authoring a new `.md` agent definition file in `.claude/agents/` | Spawning multiple already-defined agents that coordinate as a team | | Configuring a single agent's `model`, `allowed-tools`, or `context: fork` | Setting up a lead/teammate architecture with a shared task list | | Constraining tool access for a specialised read-only or write-restricted agent | Sequencing parallel work across worktrees (see parallel-agent-dispatch) | | Writing the system prompt that defines what one agent does | Auditing existing agent definitions for security (see meta-audit) | ## Core Concepts **Custom agents** let you define specialized agent types beyond the built-in ones (Explore, Plan, Bash, etc.). Each can have its own model, tools, and context configuration. They are defined in `.claude/agents/` or via plugin `agents/` directories, with YAML frontmatter + a markdown system prompt: ```yaml --- name: my-custom-agent description: What this agent does model: sonnet allowed-tools: Bash, Read, Grep, Glob --- # Agent System Prompt Instructions and context for the agent... ``` ## Key Fields ### Context Forking | Valu...