stop · MCP-Prototype MCP: Risk & Policy

WHAT IT DOES

What stop does on MCP-Prototype

AI agents invoke stop to trigger actions in MCP-Prototype. 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 stop needs a policy

This tool executes an action that stops a running web server process. While not destructive (the prototype data is not deleted), it actively terminates external operations and services. This qualifies as Execute rather than Write because it triggers system-level operations (process termination) rather than data modification.

From the tool's definition Tool description states '停止展示原型，并关闭web服务器' (stop displaying prototype and close the web server). This triggers external operations—terminating a web server process—whose effects depend on the server state at invocation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

stop Rate-limited

stop 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": {
    "stop": {
      "limits": [
        {
          "counter": "stop_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 MCP-Prototype, so you can run agents against it safely.

FAQ

Questions about stop

What does the stop tool do? +

停止展示原型，并关闭web服务器. It is categorised as a Execute tool in the MCP-Prototype MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on stop? +

Register the MCP-Prototype MCP server in PolicyLayer and add a rule for stop: 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 MCP-Prototype. Nothing to install.

What risk level is stop? +

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

Can I rate-limit stop? +

Yes. Add a rate_limit block to the stop 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 stop completely? +

Set action: deny in the PolicyLayer policy for stop. 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 stop? +

stop is provided by the MCP-Prototype MCP server (llxxbb/mcp-prototype). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.