Agent Tool Builder Agent Skill

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

529 tokens

context cost

the whole folder, loaded on every use

files

instructions only

copies elsewhere

how many repositories repackaged it

505

stars on the repo

on the repository, not the skill itself

Install

one command, takes just this skill from the repository

npx skills add https://github.com/Dokhacgiakhoa/Agent-Skills-4-Vibe-Coding-CLI --skill agent-tool-builder

What comes with it

398 bytes besides the instruction

sub-skills/silent-failures.md

sub-skills/too-many-tools.md

sub-skills/tool-error-handling.md

sub-skills/tool-schema-design.md

sub-skills/tool-with-input-examples.md

sub-skills/vague-descriptions.md

The instruction itself

10 sections, as written by the author

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

🧠 Knowledge Modules (Fractal Skills)

1. Tool Schema Design

2. Tool with Input Examples

3. Tool Error Handling

4. ❌ Vague Descriptions

5. ❌ Silent Failures

6. ❌ Too Many Tools

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Replace with description of the skill and when Claude should use it.

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This skill should be used when the user wants to "create a skill", "add a skill to plugin", "write a new skill", "improve skill description", "organize skill content", or needs guidance on skill structure, progressive disclosure, or skill development best practices for Claude Code plugins.

Helps users discover and install agent skills when they ask questions like "how do I do X", "find a skill for X", "is there a skill that can...", or express interest in extending capabilities. This skill should be used when the user is looking for functionality that might exist as an installable skill.

Use when creating new skills, editing existing skills, or verifying skills work before deployment

26k tokens scripts

How to use it

Copy the folder

Take dokhacgiakhoa/agent-tool-builder from the repository into ~/.claude/skills for personal use, or into .claude/skills inside a project.

Check the name does not clash

The agent identifies a skill by the name field in its header. Two skills with the same name cannot sit side by side — one of them will be ignored.