lights_control · Homeassistant MCP: Risk & Policy

WHAT IT DOES

What lights_control does on Homeassistant

AI agents invoke lights_control to trigger actions in Homeassistant. 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 lights_control needs a policy

The tool name suggests it controls lighting devices in a smart home environment. 'Control' implies triggering external physical operations (turning lights on/off, dimming, changing color, etc.). This falls under Execute as it triggers external operations. Severity is medium because misuse could affect physical environment, cause disturbances, or waste energy, but is generally reversible.

From the tool's definition Tool name 'lights_control' on a Home Assistant MCP server that enables AI assistants to control devices and services.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

lights_control Rate-limited

lights_control 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": {
    "lights_control": {
      "limits": [
        {
          "counter": "lights_control_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 Homeassistant, so you can run agents against it safely.

FAQ

Questions about lights_control

What does the lights_control tool do? +

lights_control. It is categorised as a Execute tool in the Homeassistant MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on lights_control? +

Register the Homeassistant MCP server in PolicyLayer and add a rule for lights_control: 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 Homeassistant. Nothing to install.

What risk level is lights_control? +

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

Can I rate-limit lights_control? +

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

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

lights_control is provided by the Homeassistant MCP server (robbrad/homeassistant-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.