mcp-devtools copilot-instructions.md

Project instructions for MCP DevTools, a Go server that gives coding assistants a set of developer tools through one program. MCP, or Model Context Protocol, is a way for an assistant to call tools provided by another program.

In plain words
What is it for?
Use them when building or running the server, choosing its standard-input or HTTP connection method, running tests, or adding tools to its modular registry.
Why use it?
They explain how the project is organized, built, run, and tested, so changes follow the repository’s setup instead of guessing at commands or interfaces.

Instructions file for GitHub Copilot

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 instructions/sammcj/mcp-devtools/copilot-instructions
Clone the repo
git clone --depth 1 https://github.com/sammcj/mcp-devtools

Made for: GitHub Copilot.

Per session 4,479 This file is loaded in full into every session.
When invoked 4,479 The same file — it is already loaded in full.
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 $0.04479 $0.04479
Opus 5 $0.02240 $0.02240
Sonnet 5 $0.00896 $0.00896
Haiku 4.5 $0.00448 $0.00448

Measured yesterday against content hash 9778431d23ab, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

mcp-devtools copilot-instructions.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 yesterday.

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.

.github/copilot-instructions.md · 428 lines

How it starts

The opening of the file, as written. The whole thing — 428 lines — stays where its author put it; the contents beside it link to each section on GitHub.

GitHub Copilot Instructions for MCP DevTools

Project Overview

MCP DevTools is a single, high-performance MCP (Model Context Protocol) server written in Go that replaces many Node.js and Python-based MCP servers with one efficient binary. It provides access to essential developer tools through a unified, modular interface that can be easily extended with new tools.

Key Features:

  • Single binary solution replacing multiple resource-heavy servers
  • 16+ essential developer tools in one package
  • Built in Go for speed, efficiency, and minimal memory footprint
  • Fast startup and response times
  • Modular tool registry architecture allowing easy addition of new tools
  • Supports multiple transports: stdio (default) and streamable HTTP

Development Setup

Building the Project

# Build the server
make build

# The binary will be created at: bin/mcp-devtools

Running the Server

# Run with stdio transport (default)
make run

# Run with HTTP transport
make run-http

Testing

# Run all tests (includes external API integration tests, ~10s)
make test

# Run fast tests (skips external dependencies, ~7s)
make test-fast

# Run tests with detailed timing
make test-verbose

Linting and Code Quality

# Format code
make fmt

# Run linters and modernisation checks
make lint
# This runs: gofmt, golangci-lint, and gopls modernize

Dependencies

# Install Go dependencies
make deps

# Install all dependencies (Go + Python for document processing)
make install-all

Project Structure

mcp-devtools/
├── internal/
│   ├── tools/           # All tool implementations
│   ├── registry/        # Tool registration system
│   ├── security/        # Security framework for file/network operations
│   ├── handlers/        # MCP protocol handlers
│   ├── config/          # Configuration management
│   ├── oauth/           # OAuth functionality
│   ├── cache/           # Caching utilities
│   ├── utils/           # Utility functions
│   └── imports/         # Import management
├── tests/
│   ├── tools/           # Unit tests for tools (REQUIRED for all tools)
│   ├── benchmarks/      # Performance and token cost tests
│   ├── oauth/           # OAuth tests
│   └── unit/            # Unit tests for internal packages
├── docs/
│   └── tools/           # Tool documentation (REQUIRED when adding tools)
├── main.go              # Entry point - import new tools here
├── Makefile             # Build, test, and development commands
└── mcp.json             # MCP server configuration

Read the full file on GitHub · 428 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. yesterday First seen · 428 lines · 4,479 tokens per session scan A 9778431d23ab

Subscribe to this mod's changes

mcp-devtools copilot-instructions.md is an instructions file published in the GitHub repository sammcj/mcp-devtools (159 stars, last pushed yesterday), licensed Apache-2.0. It adds 4,479 tokens to every session, about $0.0224 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.