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.
git clone --depth 1 https://github.com/TheSethRose/DevRulesWrote 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/rules/thesethrose/devrules/03-mcp-configuration)<a href="https://agentmods.dev/rules/thesethrose/devrules/03-mcp-configuration"><img src="https://agentmods.dev/badge/rules/thesethrose/devrules/03-mcp-configuration/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.
<a href="https://agentmods.dev/rules/thesethrose/devrules/03-mcp-configuration"><img src="https://agentmods.dev/badge/rules/thesethrose/devrules/03-mcp-configuration.svg" alt="Reviewed on agentmods" width="80" 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 | $0.00031 | $0.00359 |
| Opus 5.5 | $0.00012 | $0.00144 |
| Sonnet 5.5 | $0.00006 | $0.00072 |
| Haiku 4.5 | $0.00003 | $0.00036 |
Grade A, and why
03-mcp-configuration 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 1mo 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.
Copies of this mod
1 near-identical copy found in the catalogue:
- 03-mcp-configuration — 100% identical, 0 lines differ
What it actually says
MCP Server Configuration
This file documents the Model Context Protocol (MCP) servers available in your environment. It helps the AI understand which tools it can use for tasks involving memory, filesystem operations, web interaction, etc.
How to Provide Your MCP Configuration
- Open Cursor Settings (Cmd+, or Ctrl+,)
- Go to the 'MCP' section
- Click 'Add new global MCP server' (opens
mcp.json) - With
mcp.jsonopen, return to chat and provide context using @
Available MCP Servers
Example Server Format
### MCP Server Name
Purpose: Provides file system access for reading/writing files
When to Use: For file operations (read, write, check existence)
Key Commands: `read_file`, `write_file`, `file_exists`, `list_directory`
Usage Instructions: Always use absolute file paths
Server Template
### MCP Server
Purpose:
When to Use:
Key Commands:
Usage Instructions:
Access Scope:
Authentication:
Rate Limits:
Error Handling:
Important Notes
- Always use absolute paths for filesystem operations
- Tool descriptions are derived from available tool descriptions in your configuration
NOTE TO AI:
- Populate this file based on user's
.cursor/mcp.json - For each server, list name and brief description of purpose/commands
- Include relevant configuration details (paths, environment variables, etc.)
- Remove example section when populating with actual MCP servers
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.
- 1mo ago First seen · 52 lines · 31 tokens per session scan A a09443bb0e30
03-mcp-configuration is a cursor rule published in the GitHub repository TheSethRose/DevRules (26 stars, last pushed 1y ago), licensed MIT. It adds 31 tokens to every session and 359 once invoked, about $0.0001 per session on Opus 5.5. 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.
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