Borrowing it
Nothing to install: this file belongs to emmahuang-ee/mcp-dev-tools. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/emmahuang-ee/mcp-dev-tools/main/CLAUDE.mdgit clone --depth 1 https://github.com/emmahuang-ee/mcp-dev-toolsWrote 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/emmahuang-ee/mcp-dev-tools/claude-md)<a href="https://agentmods.dev/instructions/emmahuang-ee/mcp-dev-tools/claude-md"><img src="https://agentmods.dev/badge/instructions/emmahuang-ee/mcp-dev-tools/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 5.1 | $0.01745 | $0.01745 |
| Opus 5 | $0.00873 | $0.00873 |
| Sonnet 5 | $0.00349 | $0.00349 |
| Haiku 4.5 | $0.00175 | $0.00175 |
Grade A, and why
mcp-dev-tools 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 7d 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 — 206 lines — stays where its author put it; the contents beside it link to each section on GitHub.
local-dev-tools
A small, production-quality MCP (Model Context Protocol) server built on FastMCP. It gives an MCP client three read-only introspection tools for everyday local development: query a SQLite database, check whether a TCP port is listening, and summarise a Git working tree.
Project Overview
| Item | Value |
|---|---|
| Server name | local-dev-tools |
| Entry point | server.py |
| Transport | stdio |
| Framework | FastMCP 3.x |
| Python | 3.10+ (developed on 3.14; CI verifies 3.10–3.13) |
Tools
| Tool | Signature | Returns |
|---|---|---|
sqlite_query |
(db_path: str, query: str) -> str |
Aligned text table, max 50 rows, truncation note when more exist |
check_port |
(port: int, host: str = "127.0.0.1") -> dict |
{host, port, open, message} |
git_diff_summary |
(repo_path: str = ".") -> dict |
{repo_path, modified, added, deleted, renamed, untracked, total_changes} or {error} |
Design Philosophy
- Every tool is total. Tools validate their inputs and catch all internal
exceptions, returning a structured error value (
"Error: ..."or{"error": ...}) instead of raising. A bad argument degrades into a readable message rather than killing the server process the client depends on. - Read-only by construction.
sqlite_queryopens the database through afile:...?mode=roURI, so SQLite itself refuses writes — the keyword blocklist is defence in depth, not the only defence. - Bounded output. Result sets are capped at 50 rows and cells at 200
characters, so a careless
SELECT *cannot flood the client's context. - Bounded time. Port probes time out after 1 second;
gitsubprocesses after 15 seconds. No tool can hang the server. - Discoverable. Docstrings are numpydoc-formatted; FastMCP lifts the purpose, return shape, and failure conditions into the tool description and the per-parameter JSON Schema descriptions the model sees at discovery time.
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.
- 7d ago First seen · 206 lines · 1,745 tokens per session scan A 86439c531bb6
mcp-dev-tools CLAUDE.md is an instructions file published in the GitHub repository emmahuang-ee/mcp-dev-tools (0 stars, last pushed 1mo ago), licensed MIT. It adds 1,745 tokens to every session, about $0.0087 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.
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