cargo_doc · Cargo MCP Server MCP: Risk & Policy

WHAT IT DOES

What cargo_doc does on Cargo MCP Server

AI agents invoke cargo_doc to trigger actions in Cargo MCP Server. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why cargo_doc needs a policy

This tool executes the `cargo doc` command, which compiles and generates documentation artifacts. While not destructive (documentation generation is reversible via cleanup) and not a read-only query, it triggers external code execution.

From the tool's definition Tool description states "Generate documentation for a Rust project." The name and description indicate execution of `cargo doc`, which is a code generation tool that compiles documentation from source code.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

cargo_doc Rate-limited

cargo_doc stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "cargo_doc": {
      "limits": [
        {
          "counter": "cargo_doc_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Cargo MCP Server, so you can run agents against it safely.

FAQ

Questions about cargo_doc

What does the cargo_doc tool do? +

Generate documentation for a Rust project. It is categorised as a Execute tool in the Cargo MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on cargo_doc? +

Register the Cargo MCP Server MCP server in PolicyLayer and add a rule for cargo_doc: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Cargo MCP Server. Nothing to install.

What risk level is cargo_doc? +

cargo_doc is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit cargo_doc? +

Yes. Add a rate_limit block to the cargo_doc rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block cargo_doc completely? +

Set action: deny in the PolicyLayer policy for cargo_doc. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides cargo_doc? +

cargo_doc is provided by the Cargo MCP Server MCP server (seemethere/cargo-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.