agent-tool-design SKILL.md skillA
agent-tool-design from fortunto2/solo-factory is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add fortunto2/solo-factory/agent-tool-design@git:20260715.529f2dePins git:20260715.529f2de in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- fortunto2/solo-factory
- Path
templates/principles/agent-tool-design/SKILL.md- Versions recorded
- 1
- Latest version
- git:20260715.529f2de, committed Jul 15, 2026
- Size
- 12,986 bytes
- Repository stars
- 18
- License
- MIT
Design tool systems for AI agents — core/extended/deferred tiers, eval compute, batch tools, trust metadata. Use when building agent tools, reviewing tool architecture, or reducing tool count.
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
# Tool Design Principles for AI Agents Practical guide to designing tool systems for LLM-powered agents, distilled from building a PAC1 benchmark agent (Rust, 16 tools reduced to 12, tested across 7 models, 40+ tasks) and studying Codex CLI and Claude Code architectures. See `references/` for code patterns, comparison tables, and a quick checklist. --- ## 1. Tool Count Sweet Spot Every tool in the schema is a token cost and a new failure mode. Models degrade on long tool lists. **Industry reference points:** | Agent | Core | Extended/Deferred | Total in Schema | |-------|------|--------------------|-----------------| | Claude Code | 7 | 33 (deferred via ToolSearch) | 7-40 | | Codex CLI | 7 | 0 | 7 | | mini-SWE-agent | 1 (bash) | 0 | 1 | | PAC1 agent | 14 | 8 deferred | 14 active + 8 deferred | | SGR Python | 3-6 + reasoning | 0 | Union schema (structured output) | See `references/comparison.md` for full architecture comparison. **Rules:** - Start with 7 core tools. Add only when you can measure round-trip savings. - Track tool usage rate per task. Remove tools with <5% usage across benchmark. …
Read the whole file at its exact version.
How to install
mdr add fortunto2/solo-factory/agent-tool-design@sha256:902040408330fc31The line at the top of this page pins the label git:20260715.529f2de, 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.
[](https://markdownregistry.com/a/art_ogir3ggp5tdwwvhj)
6 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 1 version of this file, committed on Jul 15, 2026.
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (12986 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
fortunto2/solo-factory · 18 stars · license MIT · pushed 2026-11-08 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_ogir3ggp5tdwwvhj GET https://markdownregistry.com/api/v1/resolve?ref=fortunto2/solo-factory/agent-tool-design GET https://markdownregistry.com/api/v1/blob/902040408330fc3133d20e7b7cb16e75bd2fb3b32dc152ae645cab72052613d7
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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