Displays the publishing frequency (Hz) of a given ROS 2 topic.
AI agents call check_ros2_topic_hz to retrieve information from ROS MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool performs a read-only diagnostic operation that fetches information about a topic's publishing rate. It has no side effects, does not execute commands, does not modify data, and does not trigger any irreversible actions. The verb 'displays' and the focus on frequency inspection align with the Read category (query/fetch operations).
From the tool's definition The tool 'check_ros2_topic_hz' 'Displays the publishing frequency (Hz) of a given ROS 2 topic' — it retrieves and queries the frequency metric of a topic without modifying any state or triggering external operations.
Documented attack patterns abuse exactly the kind of access check_ros2_topic_hz gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and ROS MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for check_ros2_topic_hz:
{
"version": "1",
"default": "deny",
"tools": {
"check_ros2_topic_hz": {}
}
}check_ros2_topic_hz is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
Free to start. No card required.
Displays the publishing frequency (Hz) of a given ROS 2 topic. It is categorised as a Read tool in the ROS MCP MCP Server, which means it retrieves data without modifying state.
Register the ROS MCP server in PolicyLayer and add a rule for check_ros2_topic_hz: 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. Nothing to install.
check_ros2_topic_hz 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 check_ros2_topic_hz 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 check_ros2_topic_hz. 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.
check_ros2_topic_hz is provided by the ROS MCP server (yutarop/ros-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 24 ROS MCP tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
24 ROS MCP tools catalogued and risk-classified — across an index of 42,500+ MCP servers.