start_zone · Home Controller MCP: Risk & Policy

WHAT IT DOES

What start_zone does on Home Controller

AI agents invoke start_zone 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 start_zone needs a policy

This tool triggers an external operation (watering system activation) whose effects depend on the argument (duration in minutes). While not immediately destructive or financial, it executes a command that causes measurable real-world consequences. Misuse could lead to water waste, property damage, or resource depletion.

From the tool's definition Tool name 'start_zone' and description 'Start watering a single zone for the given number of minutes' indicates execution of a physical action (water system activation) with real-world effects.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

start_zone Rate-limited

start_zone 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": {
    "start_zone": {
      "limits": [
        {
          "counter": "start_zone_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 start_zone

What does the start_zone tool do? +

Start watering a single zone for the given number of minutes (1–180). 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 start_zone? +

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

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

Can I rate-limit start_zone? +

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

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

start_zone 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

start_zone 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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