sub_joy · ROS MCP Server MCP: Risk & Policy

WHAT IT DOES

What sub_joy does on ROS MCP Server

AI agents invoke sub_joy 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 sub_joy needs a policy

Subscribing to Joy joystick messages enables listening to and potentially processing real-time robot control commands. While subscription itself is typically read-like, in the context of a ROS system this establishes a channel for receiving control signals that directly trigger physical robot movements (as evidenced by the companion joy_* execution tools).

From the tool's definition Tool name 'sub_joy' and description '订阅 Joy 虚拟手柄消息' (subscribe to Joy virtual joystick messages) combined with sibling tools that trigger robot actions (joy_forward, joy_backward, joy_turn_left, joy_turn_right, joy_walk_in_place, joy_stand_up, joy_stop)…

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

sub_joy Rate-limited

sub_joy 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": {
    "sub_joy": {
      "limits": [
        {
          "counter": "sub_joy_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 sub_joy

What does the sub_joy tool do? +

订阅 Joy 虚拟手柄消息. 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 sub_joy? +

Register the ROS MCP Server MCP server in PolicyLayer and add a rule for sub_joy: 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 sub_joy? +

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

Can I rate-limit sub_joy? +

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

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

sub_joy 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.