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.
npx agentmods add instructions/kongyo2/mcpdevmcp/claude-mdgit clone --depth 1 https://github.com/kongyo2/mcpdevmcpWrote 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.
[](https://agentmods.dev/instructions/kongyo2/mcpdevmcp/claude-md)<a href="https://agentmods.dev/instructions/kongyo2/mcpdevmcp/claude-md"><img src="https://agentmods.dev/badge/instructions/kongyo2/mcpdevmcp/claude-md.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00520 | $0.00520 |
| Opus 5 | $0.00260 | $0.00260 |
| Sonnet 5 | $0.00104 | $0.00104 |
| Haiku 4.5 | $0.00052 | $0.00052 |
Grade A, and why
mcpdevmcp CLAUDE.md 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 3d 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.
How it starts
The opening of the file, as written. The whole thing — 53 lines — stays where its author put it; the contents beside it link to each section on GitHub.
CLAUDE.md
This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
Project Overview
MCP server that wraps the MCP Inspector CLI, enabling LLM agents to programmatically inspect, debug, and develop other MCP servers. Supports stdio (local commands) and SSE/HTTP (remote URLs) transports.
Commands
npm run build # Compile TypeScript to dist/
npm run dev # Watch mode with tsx
npm run check # Type check + lint
npm run lint # oxlint only
npm start # Run built server (node dist/index.js)
Test with MCP Inspector:
npx @modelcontextprotocol/inspector --cli --method tools/list node dist/index.js
Architecture
src/index.ts # Entry point - creates McpServer with StdioServerTransport
src/tools/inspector.ts # Tool registration using server.registerTool()
src/services/inspector-cli.ts # CLI wrapper - spawns Inspector CLI process
src/utils/result.ts # Command execution with ResultAsync (neverthrow)
src/types.ts # Type definitions and error kinds
Data Flow: Tool call → tools/inspector.ts handler → inspector-cli.ts service → spawns node @modelcontextprotocol/inspector/cli/build/cli.js → parses JSON output
Key Pattern: For stdio commands like "node server.js", the target string must be split into separate CLI arguments. URLs are passed as-is. See splitCommand() in inspector-cli.ts.
Error Handling
Uses neverthrow Result types throughout. Never throw exceptions in business logic:
ResultAsync<T, InspectorError>for async operationsResult<T, InspectorError>for sync operations- Error kinds:
SPAWN_FAILED,EXECUTION_FAILED,PARSE_FAILED,TIMEOUT,INVALID_RESPONSE,CONNECTION_FAILED
Tools Exposed
Six tools for inspecting target MCP servers:
mcpdev_inspector_list_tools/mcpdev_inspector_call_toolmcpdev_inspector_list_resources/mcpdev_inspector_read_resourcemcpdev_inspector_list_prompts/mcpdev_inspector_get_prompt
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.
- 3d ago First seen · 53 lines · 520 tokens per session scan A b70f663d7f67
mcpdevmcp CLAUDE.md is an instructions file published in the GitHub repository kongyo2/mcpdevmcp (0 stars, last pushed 8mo ago), licensed MIT. It adds 520 tokens to every session, about $0.0026 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 2026-08-31.
Other instructions, from other repositories
vscode buildNext.instructions.md
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
spec-kit AGENTS.md
AGENTS.md instructions for github/spec-kit, covering agents.md, about spec kit and specify, quickstart — add a new integration in 5 steps, integration architecture and integrationmanifest — file tracking.
codex AGENTS.md
AGENTS.md instructions for openai/codex, covering rust/codex-rs, the codex-core crate, code review rules, crate api surface and model visible context.
langchain AGENTS.md
AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, applying the notice (cutover) and fallback chain (never fail the build).
next.js AGENTS.md
Instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.