openems_create_horn · Mcp Openems MCP: Risk & Policy

WHAT IT DOES

What openems_create_horn does on Mcp Openems

AI agents use openems_create_horn to create or update resources in Mcp Openems — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Mcp Openems environment.

WHY IT NEEDS A POLICY

Why openems_create_horn needs a policy

This tool generates/creates a horn antenna design with calculated dimensions. It produces a new design structure (Write), with no code execution, deletion, or financial implications. Severity is low since it only creates a local design object within the simulation environment.

From the tool's definition 'Design a pyramidal horn antenna' and 'Calculates aperture dimensions and length' — creates a new antenna design artifact

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

openems_create_horn Rate-limited

openems_create_horn stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "openems_create_horn": {
      "limits": [
        {
          "counter": "openems_create_horn_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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 Openems, so you can run agents against it safely.

FAQ

Questions about openems_create_horn

What does the openems_create_horn tool do? +

Design a pyramidal horn antenna for specified gain. Calculates aperture dimensions and length. It is categorised as a Write tool in the Mcp Openems MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on openems_create_horn? +

Register the Mcp Openems MCP server in PolicyLayer and add a rule for openems_create_horn: 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 Openems. Nothing to install.

What risk level is openems_create_horn? +

openems_create_horn is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit openems_create_horn? +

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

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

openems_create_horn is provided by the Mcp Openems MCP server (rfingadam/mcp-openems). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.