agent-tool-builder SKILL.md skillA

agent-tool-builder from hybridlabor-api/bdb-dev-optimized-agent-skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.

Install it, pinned
mdr add hybridlabor-api/bdb-dev-optimized-agent-skills/agent-tool-builder@git:20261020.63f1c38

Pins git:20261020.63f1c38 in mdr.lock. Pin the fingerprint instead.

Audit grade
A, 17 of 17 checks passed
Kind
SKILL.md skill
Repository
hybridlabor-api/bdb-dev-optimized-agent-skills
Path
skills/global_config/agent-tool-builder/SKILL.md
Versions recorded
7
Latest version
git:20261020.63f1c38, committed Oct 20, 2026
First version recorded
Jul 27, 2026
Size
19,070 bytes
Repository stars
7
License
Apache-2.0

Design tools for AI agents. Use when building agent tools: covers schema, error handling, and avoiding hallucination and silent failure.

Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.

What the file says

# 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 implementations.
The LLM never sees your code - it only sees the schema and description.

## Principles

- Description quality > implementation quality for LLM accuracy
- Aim for fewer than 20 tools - more causes confusion
- Every tool needs explicit error handling - silent failures poison agents
- Return strings, not objects - LLMs process text
- Validation gates before execution - reject, fix, or escalate, never silent fail
- Test tools with the LLM, not just unit tests

## Capabilities

- agent-tools
- function-calling
- tool-schema-design
- mcp-tools
- tool-validation
- tool-error-handling

## Scope

- multi-agent-coordination → multi-agent-orchestration
…

Read the whole file at its exact version.

How to install

The exact contents, by fingerprint
mdr add hybridlabor-api/bdb-dev-optimized-agent-skills/agent-tool-builder@sha256:04f5d9d209203aca

The line at the top of this page pins the label git:20261020.63f1c38, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.

Badge

mdr badge

[![mdr](https://markdownregistry.com/badge/art_tjqu6fuywezfqe5q.svg)](https://markdownregistry.com/a/art_tjqu6fuywezfqe5q)

6 badge image fetches in 30 days. What the badge shows.

Versions

The registry has recorded 7 versions of this file, between Jul 27, 2026 and Oct 20, 2026, about one every 14 days.

versioncommittedcommitsizeaudit
git:20261020.63f1c38 latest2026-10-20 63f1c38 19,070 BA view · diff
git:20261015.2992fd92026-10-15 2992fd9 19,121 BA view · diff
git:20261007.97ebebf2026-10-07 97ebebf 19,200 BA view · diff
git:20261007.5ed94c22026-10-07 5ed94c2 19,120 BA view · diff
git:20260912.72cd8a32026-09-12 72cd8a3 19,122 BA view · diff
git:20260827.e4036aa2026-08-27 e4036aa 19,117 BA view · diff
git:20260727.48beb342026-07-27 48beb34 19,088 BA view

Audit of the latest version

A  17 of 17 checks passed. Fixed automatic checks with no AI involved, so the same checks give the same answer every run.
  • pass: Frontmatter block present
  • pass: Frontmatter declares a name
  • pass: Frontmatter declares a description
  • pass: Size between 200 bytes and 200 KB (19070 bytes)
  • pass: No zero-width or bidi control characters
  • pass: No instruction hidden inside an HTML comment
  • pass: No link to an exfiltration or paste host
  • pass: No credential-shaped string
  • pass: No instruction to send local credentials anywhere
  • pass: No text hidden with inline styles
  • pass: No prompt-injection phrasing
  • pass: No curl or wget piped into a shell
  • pass: No recursive delete of root, home or parent
  • pass: No instruction to read or print local credentials
  • pass: No base64 blob over 200 characters
  • pass: No link to a raw IP address
  • pass: No script tag

Source

GitHub

hybridlabor-api/bdb-dev-optimized-agent-skills · 7 stars · license Apache-2.0 · pushed 2026-11-05 · branch main

API

GET https://markdownregistry.com/api/v1/artifacts/art_tjqu6fuywezfqe5q
GET https://markdownregistry.com/api/v1/resolve?ref=hybridlabor-api/bdb-dev-optimized-agent-skills/agent-tool-builder
GET https://markdownregistry.com/api/v1/blob/04f5d9d209203aca9980e7795207fe8ffd89567797bc5285c45e70c99b9a52e7

Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.

Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.

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