Agent skill · Documentation

agent-tool-builder

Tools are how AI agents interact with the world. A well-designed tool is the difference between an agent that works and one that hallucinates, fails silently, or costs 10x more tokens than necessary. This skill covers tool design from schema to error handling. JSON Schema best practices, description writing that actually helps the LLM, validation, and the emerging MCP standard that's becoming the lingua franca for AI tools. Key insight: Tool descriptions are more important than tool implementa

majiayu000github.com/majiayu000GitHub ↗
claude-codeMIT
Install
npx skills add majiayu000/claude-skill-registry --skill agent-tool-builder-agent-skills-hub-agent-skills-hub --agent claude-code

Same command for any agent — swap --agent for codex, cursor, copilot.

Facts
Files in the skill folder: 2
SKILL.md size: 2 KB
Bundled scripts: none
Path: skills/agent/agent-tool-builder-agent-skills-hub-agent-skills-hub/SKILL.md
Open the folder on GitHub →
Where it comes from
Stars: 534
Language: HTML

Weekly change comes from our own snapshots, not the repository page — it measures attention, not adoption.

From the SKILL.md

# Agent Tool Builder You are an expert in the interface between LLMs and the outside world. You've seen tools that work beautifully and tools that cause agents to hallucinate, loop, or fail silently. The difference is almost always in the design, not the implementation. Your core insight: The LLM never sees your code. It only sees the schema and description. A perfectly implemented tool with a vague description will fail. A simple tool with crystal-clear documentation will succeed. You push for explicit error hand ## Capabilities - agent-tools - function-calling - tool-schema-design - mcp-tools - tool-validation - tool-error-handling ## Patterns ### Tool Schema Design Creating clear, unambiguous JSON Schema for tools ### Tool with Input Examples Using examples to guide LLM tool usage ### Tool Error Handling Returning errors that help the LLM recover ## Anti-Patterns ### ❌ Vague Descriptions ### ❌ Silent Failures ### ❌ Too Many Tools ## Related Skills Works well with: `multi-agent-orchestration`, `api-designer`, `llm-architect`, `backend`

What's inside
Steps it walks through
  1. Capabilities
  2. Patterns
  3. Tool Schema Design
  4. Tool with Input Examples
  5. Tool Error Handling
  6. Anti-Patterns
  7. ❌ Vague Descriptions
  8. ❌ Silent Failures
  9. ❌ Too Many Tools
  10. Related Skills
Ships with 1 file
  • metadata.json
More from claude-skill-registry
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About this skill
What does the agent-tool-builder skill do?

Tools are how AI agents interact with the world. A well-designed tool is the difference between an agent that works and one that hallucinates, fails silently, or costs 10x more tokens than necessary. This skill covers tool design from schema to error handling. JSON Schema best practices, description writing that actually helps the LLM, validation, and the emerging MCP standard that's becoming the lingua franca for AI tools. Key insight: Tool descriptions are more important than tool implementa

How do I install it?

Run `npx skills add majiayu000/claude-skill-registry --skill agent-tool-builder-agent-skills-hub-agent-skills-hub --agent claude-code` — it drops the skill into your project so the agent can pick it up. Swap the --agent value for codex, cursor or copilot if you use one of those.

Where does this skill come from?

From majiayu000/claude-skill-registry, a repository with 534 stars. We read it straight from the repository tree rather than a submitted listing, so what you see here is what is actually published.

Is a popular skill a good skill?

Not necessarily. Stars measure attention, not adoption — a repository can trend for a week and be abandoned. That is why we show the weekly change from our own snapshots next to the total, instead of a single flattering number.

Keep going