set_temperature · Home Controller MCP: Risk & Policy

WHAT IT DOES

What set_temperature does on Home Controller

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

WHY IT NEEDS A POLICY

Why set_temperature needs a policy

This tool modifies a device setting (water temperature target) on a connected smart home appliance. It creates a reversible change to a configuration value. Misuse could result in water being set to dangerously high temperatures (up to 140°F, which can cause scalding), giving it a medium severity. It does not delete data or execute arbitrary code, so Write is the most appropriate category.

From the tool's definition Set the target water temperature (95-140°F)

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

set_temperature Rate-limited

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

FAQ

Questions about set_temperature

What does the set_temperature tool do? +

Set the target water temperature (95-140°F). It is categorised as a Write tool in the Home Controller MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on set_temperature? +

Register the Home Controller MCP server in PolicyLayer and add a rule for set_temperature: 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 set_temperature? +

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

Can I rate-limit set_temperature? +

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

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

set_temperature 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.

// THE FULL RECORD

set_temperature is one line of Home Controller's registry record.

The record carries the whole server: verified identity, auth posture, risk grade, every tool classified, recommended policy — re-checked continuously.

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