mcp-builder

mcp-builder is a skill for Claude Code from SKB3002/agenthub. It costs 24 tokens per session (989 once invoked), scanned A, original, no licence file.

A guide to building MCP servers. MCP, or Model Context Protocol, is a standard way for AI assistants to access tools and other information.

In plain words
What is it for?
Use it when creating an MCP server, designing assistant tools, exposing resources, or reviewing MCP implementation choices.
Why use it?
It helps you design the tools and information exposed to an AI assistant in a consistent way. This reduces guesswork when deciding how an MCP server should be structured.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Part of the hub plugin — 53 skills, 37 commands, 20 agents shipped together

Good fit Use it when creating an MCP server, designing assistant tools, exposing resources, or reviewing MCP implementation choices.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/skb3002/agenthub/mcp-builder
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.

Any agent
npx skills add SKB3002/agenthub --skill mcp-builder
Clone the repo
git clone --depth 1 https://github.com/SKB3002/agenthub

Made for: Claude Code.

Or install hub, the plugin that ships this one along with the rest of its 53 skills, 37 commands, 20 agents.

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 mcp-builder

README.md
[![agentmods](https://agentmods.dev/badge/skills/skb3002/agenthub/mcp-builder/github.svg)](https://agentmods.dev/skills/skb3002/agenthub/mcp-builder)
Your own site
<a href="https://agentmods.dev/skills/skb3002/agenthub/mcp-builder"><img src="https://agentmods.dev/badge/skills/skb3002/agenthub/mcp-builder/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for mcp-builder

Your own site · 80×15
<a href="https://agentmods.dev/skills/skb3002/agenthub/mcp-builder"><img src="https://agentmods.dev/badge/skills/skb3002/agenthub/mcp-builder.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 24 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 989 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin unknown 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 5.1 $0.00024 $0.00989
Opus 5.5 $0.00010 $0.00396
Sonnet 5.5 $0.00005 $0.00198
Haiku 4.5 $0.00002 $0.00099

Measured 1mo ago against content hash c6cb4358e6f1, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

mcp-builder 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 1mo 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.

plugins/hub/skills/mcp-builder/SKILL.md · 210 lines

The source is not reproduced here

A licence we could not identify

The repository carries a LICENSE file, but it is custom or dual enough that GitHub cannot name it and neither can this catalogue. Unknown terms are not permission, so the body is not copied here. Read the licence at the source and decide for yourself.

Read it on GitHub

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. 1mo ago First seen · 210 lines · 24 tokens per session scan A c6cb4358e6f1

Subscribe to this mod's changes

mcp-builder is a skill published in the GitHub repository SKB3002/agenthub (4 stars, last pushed 5mo ago), with no licence file. It adds 24 tokens to every session and 989 once invoked, about $0.0001 per session on Opus 5.5. 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 2026-09-03.

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