30-mcp-safety

30-mcp-safety is a cursor rule for Cursor from felipeblassioli/agent-skills. It costs 27 tokens per session (162 once invoked), scanned A, original, no licence file.

Rules for configuring MCP servers, which let an agent connect to external tools and data sources. They require checking where a server comes from, limiting its access, using environment-variable substitution, and separating examples from live configuration.

In plain words
What is it for?
Use them when adding or reviewing MCP server settings, deciding what scope a connection needs, handling secrets, or distinguishing sample configuration from active settings.
Why use it?
They reduce the risk of exposing too much access or accidentally using unsafe configuration.

Cursor rule for Cursor

Written for Cursor: installed under .cursor/.

Good fit Use them when adding or reviewing MCP server settings, deciding what scope a connection needs, handling secrets, or distinguishing sample configuration from active settings.

Compare 6 cursor rules from other repositories ↓
Install with agentmods
npx agentmods add rules/felipeblassioli/agent-skills/30-mcp-safety
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.

Clone the repo
git clone --depth 1 https://github.com/felipeblassioli/agent-skills

Made for: Cursor.

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 30-mcp-safety

README.md
[![agentmods](https://agentmods.dev/badge/rules/felipeblassioli/agent-skills/30-mcp-safety/github.svg)](https://agentmods.dev/rules/felipeblassioli/agent-skills/30-mcp-safety)
Your own site
<a href="https://agentmods.dev/rules/felipeblassioli/agent-skills/30-mcp-safety"><img src="https://agentmods.dev/badge/rules/felipeblassioli/agent-skills/30-mcp-safety/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 30-mcp-safety

Your own site · 80×15
<a href="https://agentmods.dev/rules/felipeblassioli/agent-skills/30-mcp-safety"><img src="https://agentmods.dev/badge/rules/felipeblassioli/agent-skills/30-mcp-safety.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 27 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 162 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 $0.00027 $0.00162
Opus 5 $0.00014 $0.00081
Sonnet 5 $0.00005 $0.00032
Haiku 4.5 $0.00003 $0.00016

Measured 10d ago against content hash 277e299a5a1f, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

30-mcp-safety 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 10d 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.

packs/cursor-companion/.cursor/rules/30-mcp-safety.mdc · 21 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

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. 10d ago First seen · 21 lines · 27 tokens per session scan A 277e299a5a1f

Subscribe to this mod's changes

30-mcp-safety is a cursor rule published in the GitHub repository felipeblassioli/agent-skills (2 stars, last pushed today), with no licence file. It adds 27 tokens to every session and 162 once invoked, about $0.0001 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.