Agent skill · product strategy · aiskillstore
building-agents
Expert at creating and modifying Claude Code agents (subagents). Auto-invokes when the user wants to create, update, modify, enhance, validate, or standardize agents, or when modifying agent YAML frontmatter fields (especially 'model', 'tools', 'description'), needs help designing agent architecture, or wants to understand agent capabilities. Also auto-invokes proactively when Claude is about to write agent files (*/agents/*.md), create modular agent architectures, or implement tasks that involve creating agent components.
Why this skill is useful
Provides detailed architecture patterns and YAML schema for creating and managing Claude Code agents, which the AI wouldn't reliably generate on its own.
What it needs
About 9k tokens when loaded. Last updated 2026-08-07. 405 stars on the source repository.
What this skill does
Building Agents Skill You are an expert at creating Claude Code agents (subagents). Agents are specialized assistants that handle delegated tasks with independent context and dedicated resources. When to Create an Agent vs Other Components Use an AGENT when: The task requires specialized, focused expertise You need independent context and isolation from the main conversation The task involves heavy computation or long-running operations You want explicit invocation rather than automatic activation The task benefits from dedicated tool permissions Use a SKILL instead when: You want automatic, context-aware assistance The expertise should be "always on" and auto-invoked You need progressive disclosure of context Use a COMMAND instead when: The user explicitly triggers a specific workflow You need parameterized inputs via command arguments Agent Schema & Structure File Location Project-level: .claude/agents/agent-name.md User-level: ~/.claude/agents/agent-name.md Plugin-level: plugin-dir/agents/agent-name.md File Format Single Markdown file with YAML frontmatter and Markdown body. Required Fields Optional Fields Note on color field: The color is displayed in the terminal when the agent is invoked, helping users visually identify which agent is running. Use a 6-digit hex color with # prefix (e.g., "#9B59B6"). Choose colors that reflect the agent's domain or plugin family for visual consistency. Note on capabilities field: This array lists specific tasks the agent specializes in, helping Claude autonomously determine when to invoke the agent. Use kebab-case strings (e.g., "analyze-security", "generate-tests", "review-architecture"). This field is recommended but optional - if omitted, Claude relies solely on the description for invocation decisions. Subagent Architecture Constraints CRITICAL: Agents run as subagents and cannot spawn other subagents. …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills aiskillstore/building-agents