stop_sauna · Home Controller MCP: Risk & Policy

WHAT IT DOES

What stop_sauna does on Home Controller

AI agents invoke stop_sauna to trigger actions in Home Controller. 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 stop_sauna needs a policy

While stopping a sauna is reversible (it can be turned back on), it is an active control operation that affects physical state in the real world and represents an Execute-category tool. It is not Destructive because the action is easily reversible and causes no data loss. It is not Write because it does not create or modify persistent data records.

From the tool's definition Tool name 'stop_sauna' and description 'Stop/turn off the sauna' indicate an action that triggers external device control with real-world effects (powering down a sauna).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

stop_sauna Rate-limited

stop_sauna 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": {
    "stop_sauna": {
      "limits": [
        {
          "counter": "stop_sauna_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 Home Controller, so you can run agents against it safely.

FAQ

Questions about stop_sauna

What does the stop_sauna tool do? +

Stop/turn off the sauna. It is categorised as a Execute tool in the Home Controller MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on stop_sauna? +

Register the Home Controller MCP server in PolicyLayer and add a rule for stop_sauna: 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 Home Controller. Nothing to install.

What risk level is stop_sauna? +

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

Can I rate-limit stop_sauna? +

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

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

stop_sauna is provided by the Home Controller MCP server (winsthuang/home-controller). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.