mcp-standards

mcp-standards is a skill for Claude Code, Codex from MadAppGang/claude-code. It costs 69 tokens per session (6,678 once invoked), scanned A, original, MIT.

A set of standards for building Model Context Protocol servers, which provide coding agents with tools, data sources, and connections to external services.

In plain words
What is it for?
Use it when implementing MCP servers, defining tool interfaces, connecting APIs or databases, or standardizing how external actions and data are exposed to an agent.
Why use it?
It helps developers design MCP integrations with consistent tool names, interfaces, transports, and configuration, making them easier to use and debug.

Skill for Claude CodeCodex

Installs and runs on its own, but its text points at files inside its plugin — anything it tells you to read at a ${CLAUDE_PLUGIN_ROOT} path is only there once the plugin is installed. Installing the plugin gets both.

Part of the dev plugin — 47 skills, 12 commands, 14 agents shipped together

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 skills/madappgang/claude-code/mcp-standards
Any agent
npx skills add MadAppGang/claude-code --skill mcp-standards
Clone the repo
git clone --depth 1 https://github.com/MadAppGang/claude-code

Made for: Claude Code, Codex.

Or install dev, the plugin that ships this one along with the rest of its 47 skills, 12 commands, 14 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-standards

README.md
[![agentmods](https://agentmods.dev/badge/skills/madappgang/claude-code/mcp-standards.svg)](https://agentmods.dev/skills/madappgang/claude-code/mcp-standards)
Your own site
<a href="https://agentmods.dev/skills/madappgang/claude-code/mcp-standards"><img src="https://agentmods.dev/badge/skills/madappgang/claude-code/mcp-standards.svg" alt="Measured on agentmods" height="20"></a>
Per session 69 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 6,678 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. 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 5.1 $0.00069 $0.06678
Opus 5 $0.00034 $0.03339
Sonnet 5 $0.00014 $0.01336
Haiku 4.5 $0.00007 $0.00668

Measured 2d ago against content hash 139df149f82a, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

mcp-standards scanned grade A with 1 finding 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 2d 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

const result = await externalAPI.fetch(id);
plugins/dev/skills/mcp-standards/SKILL.md · 1,122 lines

How it starts

The opening of the file, as written. The whole thing — 1,122 lines — stays where its author put it; the contents beside it link to each section on GitHub.

MCP Standards Skill

1. Overview

What is MCP in Claude Code?

Model Context Protocol (MCP) is the standard way to extend Claude Code with custom tools and integrations. MCP servers provide:

  • Tool Integration: Connect to external APIs, databases, and services
  • Context Providers: Supply relevant information to Claude during conversations
  • Action Handlers: Execute operations in external systems
  • Data Sources: Access project-specific or organization-specific data

Why Standardization Matters

Standardized MCP servers ensure:

  1. Predictable Behavior: Developers know what to expect from MCP tools
  2. Easier Debugging: Consistent patterns make issues easier to identify
  3. Better Discoverability: Standard naming helps Claude and users find tools
  4. Maintainability: Common patterns reduce maintenance burden
  5. Team Consistency: Multiple developers follow same conventions

MCP in the Plugin Ecosystem

MCP servers are plugin components alongside agents, commands, and skills:

plugin/
├── agents/          # Specialized Claude instances
├── commands/        # CLI commands
├── skills/          # Knowledge documents
└── mcp-servers/     # MCP tool providers ← We're here

Key Difference: While agents use built-in tools, MCP servers provide NEW tools that extend Claude's capabilities.


2. MCP Server Structure

Standard Directory Layout

mcp-servers/
├── server-name/
│   ├── index.ts                  # Server entry point
│   ├── package.json              # Dependencies and metadata
│   ├── tsconfig.json             # TypeScript configuration
│   ├── README.md                 # Server documentation
│   ├── tools/                    # Tool implementations
│   │   ├── read-tool.ts
│   │   ├── write-tool.ts
│   │   └── index.ts              # Tool exports
│   ├── lib/                      # Shared utilities
│   │   ├── client.ts             # API client
│   │   ├── validation.ts         # Input validation
│   │   └── errors.ts             # Error handling
│   └── tests/                    # Test files
│       ├── read-tool.test.ts
│       └── write-tool.test.ts

Read the full file on GitHub · 1,122 lines

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. 2d ago First seen · 1,122 lines · 69 tokens per session scan A 139df149f82a

Subscribe to this mod's changes

mcp-standards is a skill published in the GitHub repository MadAppGang/claude-code (279 stars, last pushed 5mo ago), licensed MIT. It adds 69 tokens to every session and 6,678 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.