Echo messages from a topic
AI agents call echo_topic to retrieve information from ROS 2 MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
Echoing topic messages is a read-only operation that queries and retrieves published data from a ROS 2 topic. It has no side effects, does not modify system state, and does not execute arbitrary code. The severity is low because observing topic data poses minimal risk—it is passive introspection. Confidence is high because the description unambiguously describes a retrieval action.
From the tool's definition Tool name 'echo_topic' and description 'Echo messages from a topic' indicate retrieval and observation of ROS 2 topic data without modification, deletion, or execution of external operations.
Attacks that exploit this kind of access
Echo messages from a topic. It is categorised as a Read tool in the ROS 2 MCP Server MCP Server, which means it retrieves data without modifying state.
Register the ROS 2 MCP Server MCP server in PolicyLayer and add a rule for echo_topic: 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 2 MCP Server. Nothing to install.
echo_topic is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the echo_topic 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.
Set action: deny in the PolicyLayer policy for echo_topic. 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.
echo_topic is provided by the ROS 2 MCP Server MCP server (ranch-hand-robotics/rde-mcp-ros-2). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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