mcp-tools

mcp-tools is a cursor rule for Cursor from Excoriate/mcp-terraform-aws-provider-docs. It costs 668 tokens per session, scanned A, original, MIT.

A rule for writing MCP tool definitions, where MCP is a standard way for an agent to use external tools. It requires each tool to document its purpose, inputs, outputs, edge cases, integrations, and an example.

In plain words
What is it for?
For defining JavaScript MCP tools and documenting their arguments, results, errors, pagination, and possible combinations with other tools.
Why use it?
It prevents tool descriptions from being incomplete or inconsistent, so users and agents can understand how each tool should behave.

Cursor rule for Cursor

Written for Cursor: installed under .cursor/.

Good fit For defining JavaScript MCP tools and documenting their arguments, results, errors, pagination, and possible combinations with other tools.

Compare 6 cursor rules from other repositories ↓
Install with agentmods
npx agentmods add rules/excoriate/mcp-terraform-aws-provider-docs/mcp-tools
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/Excoriate/mcp-terraform-aws-provider-docs

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-tools

README.md
[![agentmods](https://agentmods.dev/badge/rules/excoriate/mcp-terraform-aws-provider-docs/mcp-tools.svg)](https://agentmods.dev/rules/excoriate/mcp-terraform-aws-provider-docs/mcp-tools)
Your own site
<a href="https://agentmods.dev/rules/excoriate/mcp-terraform-aws-provider-docs/mcp-tools"><img src="https://agentmods.dev/badge/rules/excoriate/mcp-terraform-aws-provider-docs/mcp-tools.svg" alt="Measured on agentmods" height="20"></a>
Per session 668 This file is loaded in full into every session.
When invoked 668 The same file — it is already loaded in full.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00668 $0.00668
Opus 5 $0.00334 $0.00334
Sonnet 5 $0.00134 $0.00134
Haiku 4.5 $0.00067 $0.00067

Measured 8d ago against content hash 7e26c6e9d9f7, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

mcp-tools 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 8d 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.

.cursor/rules/mcp-tools.mdc · 52 lines

How it starts

The opening of the file, as written. The whole thing — 52 lines — stays where its author put it; the contents beside it link to each section on GitHub.

MCP Tool Definition Rule

Canonical Example

See tools-issues.ts for a complete, high-quality MCP tool definition.

Required Structure for All MCP Tools

Every MCP tool must be defined as a JavaScript object with the following fields:

  • name: A unique, descriptive string identifier for the tool.
  • description: A multiline template string (using backticks) containing a plain-text, sectioned, and indented description. Do not use markdown or code block syntax inside the content. The description must be readable in code and must include the following sections, in order:
    • Purpose: What the tool does and why it exists.
    • When to Use: Actionable scenarios for LLMs and users.
    • Arguments: List each argument, its type, and its effect. For booleans, clarify behavior for true/false. For pagination or filtering, be explicit.
    • Output Format: Describe the structure and fields of the output, including types and any formatting conventions.
    • Edge Case Handling: Explicitly document all edge cases (empty results, pagination, missing fields, authentication errors, etc.).
    • Integration and Chaining: How this tool can be combined with other tools or workflows.
    • Example Usage: At least two example invocations, formatted as plain text (not JSON or markdown).
    • Success Criteria: List the conditions for correct and robust tool behavior.
  • inputSchema: An explicit schema object describing all accepted arguments, with each field’s description clarifying its behavior and effect.

Formatting and Content Requirements

  • Use a multiline template string for the description. Do not use markdown, code blocks, or backticks inside the content.
  • Indent and line-break sections for maximum readability in code.
  • All field names and values in the description should be plain text.
  • Argument descriptions must clarify the effect of each value (e.g., “Controls pagination behavior - when true, fetches all pages of issues; when false, only returns the first page (30 issues)”).
  • Output format must list all fields, types, and any special formatting or conventions.
  • Edge case handling is mandatory and must be explicit.
  • Example usage must be included as plain text, not as markdown or code blocks.

Read the full file on GitHub · 52 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. 8d ago First seen · 52 lines · 668 tokens per session scan A 7e26c6e9d9f7

Subscribe to this mod's changes

mcp-tools is a cursor rule published in the GitHub repository Excoriate/mcp-terraform-aws-provider-docs (1 stars, last pushed 1y ago), licensed MIT. It adds 668 tokens to every session, about $0.0033 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.