mcp-and-tool-security

mcp-and-tool-security is a cursor rule for Cursor from kristiyan-velkov/ai-security-rules. It costs 0 tokens per session (367 once invoked), scanned A, original, no licence file.

A set of security rules for MCP servers, AI agent tools, and outside integrations. MCP is a way for an AI assistant to connect to tools and data sources.

In plain words
What is it for?
Use it when reviewing or configuring agent tools, MCP servers, and third-party connections for security weaknesses.
Why use it?
It focuses on supply-chain risks and SSRF, an attack that tricks a server into making requests to unintended internal or external addresses.

Cursor rule for Cursor

Written for Cursor: installed under .cursor/.

Good fit Use it when reviewing or configuring agent tools, MCP servers, and third-party connections for security weaknesses.

Compare 6 cursor rules from other repositories ↓
Install with agentmods
npx agentmods add rules/kristiyan-velkov/ai-security-rules/mcp-and-tool-security
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/kristiyan-velkov/ai-security-rules

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 mcp-and-tool-security

README.md
[![agentmods](https://agentmods.dev/badge/rules/kristiyan-velkov/ai-security-rules/mcp-and-tool-security/github.svg)](https://agentmods.dev/rules/kristiyan-velkov/ai-security-rules/mcp-and-tool-security)
Your own site
<a href="https://agentmods.dev/rules/kristiyan-velkov/ai-security-rules/mcp-and-tool-security"><img src="https://agentmods.dev/badge/rules/kristiyan-velkov/ai-security-rules/mcp-and-tool-security/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 mcp-and-tool-security

Your own site · 80×15
<a href="https://agentmods.dev/rules/kristiyan-velkov/ai-security-rules/mcp-and-tool-security"><img src="https://agentmods.dev/badge/rules/kristiyan-velkov/ai-security-rules/mcp-and-tool-security.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 367 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. 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 $0.00000 $0.00367
Opus 5.5 $0.00000 $0.00147
Sonnet 5.5 $0.00000 $0.00073
Haiku 4.5 $0.00000 $0.00037

Measured 10d ago against content hash b14b7c7c0895, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

mcp-and-tool-security 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 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.

Reads agent configuration directorieslowAgent snooping

.claude/, .codex/, .gemini/ hold keys, settings and other credentials a mod has no legitimate need for.

globs: "**/.cursor/mcp.json,**/mcp.json,**/.mcp/**,**/claude_desktop_config.json,**/.claude/settings.json,**/.claude/settings.local.json"

Downgraded: this mod is about security review, or the phrase is quoted, so it is likely naming the pattern rather than instructing it.

.cursor/rules/general/mcp-and-tool-security.mdc · 27 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 · 27 lines · 0 tokens per session scan A b14b7c7c0895

Subscribe to this mod's changes

mcp-and-tool-security is a cursor rule published in the GitHub repository kristiyan-velkov/ai-security-rules (4 stars, last pushed 11d ago), with no licence file. It costs nothing until one of its globs matches a file; then it loads 367 tokens. A static security scan graded it A with 1 finding (reads agent configuration directories). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-10-17.