script_control · Homeassistant MCP: Risk & Policy

WHAT IT DOES

What script_control does on Homeassistant

AI agents invoke script_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 script_control needs a policy

Based on the tool name, 'script_control' almost certainly triggers or manages Home Assistant scripts, which are sequences of actions executed against smart home devices. This falls under Execute as it runs predefined automations/scripts with potentially wide physical effects (lights, locks, alarms, etc.).

From the tool's definition Tool name 'script_control' on a Home Assistant MCP server; description is empty and uninformative.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

script_control Rate-limited

script_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": {
    "script_control": {
      "limits": [
        {
          "counter": "script_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 script_control

What does the script_control tool do? +

script_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 script_control? +

Register the Homeassistant MCP server in PolicyLayer and add a rule for script_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 script_control? +

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

Can I rate-limit script_control? +

Yes. Add a rate_limit block to the script_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 script_control completely? +

Set action: deny in the PolicyLayer policy for script_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 script_control? +

script_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.