joy_stop · ROS MCP Server MCP: Risk & Policy

WHAT IT DOES

What joy_stop does on ROS MCP Server

AI agents invoke joy_stop to trigger actions in ROS 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 joy_stop needs a policy

This tool executes an external operation (robot motor control) whose effects are physically observable and depend on robot state/environment. While not destructive (robot can reverse the action), it is Execute-category because it triggers autonomous physical actions in the real world.

From the tool's definition Tool name 'joy_stop' with description '机器人坐下' (robot sit down) is a direct robot control command that triggers physical movement.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

joy_stop Rate-limited

joy_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": {
    "joy_stop": {
      "limits": [
        {
          "counter": "joy_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 ROS MCP Server, so you can run agents against it safely.

FAQ

Questions about joy_stop

What does the joy_stop tool do? +

机器人坐下. It is categorised as a Execute tool in the ROS 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 joy_stop? +

Register the ROS MCP Server MCP server in PolicyLayer and add a rule for joy_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 ROS MCP Server. Nothing to install.

What risk level is joy_stop? +

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

Can I rate-limit joy_stop? +

Yes. Add a rate_limit block to the joy_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 joy_stop completely? +

Set action: deny in the PolicyLayer policy for joy_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 joy_stop? +

joy_stop is provided by the ROS MCP Server MCP server (moneypiaorui/ros-mcp-server-minipi). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.