tool-designer

tool-designer is an agent for Claude Code from hollobit/assembly-api-mcp. It costs 31 tokens per session (332 once invoked), scanned A, original, MIT.

An MCP tool design agent that plans interfaces for AI clients such as Claude, ChatGPT, and Cursor.

In plain words
What is it for?
Use it to review tool descriptions and schemas, design user-focused parameters, detect semantic overlap, plan automatic mode selection, and decide which tools belong in Lite or Full profiles.
Why use it?
It helps prevent overlapping tools and overly large descriptions while making it easier for an AI client to choose the right tool and parameters.

Agent for Claude Code

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add agents/hollobit/assembly-api-mcp/tool-designer
Clone the repo
git clone --depth 1 https://github.com/hollobit/assembly-api-mcp

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for tool-designer

README.md
[![agentmods](https://agentmods.dev/badge/agents/hollobit/assembly-api-mcp/tool-designer.svg)](https://agentmods.dev/agents/hollobit/assembly-api-mcp/tool-designer)
Your own site
<a href="https://agentmods.dev/agents/hollobit/assembly-api-mcp/tool-designer"><img src="https://agentmods.dev/badge/agents/hollobit/assembly-api-mcp/tool-designer.svg" alt="Measured on agentmods" height="20"></a>
Per session 31 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 332 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00031 $0.00332
Opus 5 $0.00015 $0.00166
Sonnet 5 $0.00006 $0.00066
Haiku 4.5 $0.00003 $0.00033

Measured 5d ago against content hash e3321f3c6cbb, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

tool-designer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 5d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.claude/agents/tool-designer.md · 31 lines

What it actually says

Tool Designer Agent

MCP 도구의 인터페이스를 AI 에이전트 관점에서 분석하고 최적화하는 전문 에이전트입니다.

역할

  • 도구 description과 파라미터 스키마의 토큰 효율 분석
  • AI 클라이언트(Claude, ChatGPT, Cursor)별 도구 선택 정확도 평가
  • 도구 간 의미 겹침(semantic overlap) 감지 및 해소
  • 파라미터 자동 감지 로직 설계
  • Lite/Full 프로필 배분 최적화

설계 원칙

  1. 도메인 엔티티 기반: API 1:1 매핑이 아닌 사용자 질문 단위
  2. 파라미터 확장 > 도구 추가: 새 기능은 기존 도구에 모드/옵션 추가
  3. 자동 감지 > 명시 지정: 파라미터 조합으로 모드 추론
  4. 실패 격리: Promise.allSettled로 부분 실패 허용
  5. 6~8개 최적 구간: LLM 도구 선택 정확도 최적 범위

출력

  • _workspace/design-{date}.md: 도구 설계 제안서
  • 파라미터 스키마, description 초안, 토큰 추정치
Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 5d ago First seen · 31 lines · 31 tokens per session scan A e3321f3c6cbb

Subscribe to this mod's changes

tool-designer is an agent published in the GitHub repository hollobit/assembly-api-mcp (89 stars, last pushed 4mo ago), licensed MIT. It adds 31 tokens to every session and 332 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.