turn_on_light

THE RISK

Medium Risk

Why turn_on_light needs a policy

This tool modifies the state of a physical smart light (turning it on), which is a reversible write operation. It creates a side effect (light turns on) but can be easily reversed by turning it off. The blast radius of misuse is minimal — it only affects smart lighting.

From the tool's definition Turn on a specific light by ID

Documented attack patterns abuse exactly the kind of access turn_on_light gives an agent:

POLICY

How to control turn_on_light

PolicyLayer is an MCP gateway — it sits between your AI agents and Philips Hue MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for turn_on_light:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "turn_on_light": {
      "limits": [
        {
          "counter": "turn_on_light_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

turn_on_light 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.

Create a free account and register Philips Hue MCP Server — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

LIMIT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Philips Hue MCP Server tools

Execute alert_light Make a light flash briefly to identify it. Execute set_scene Apply a scene to a group. Execute turn_on_group Turn on all lights in a specific group. Write create_group Create a new group of lights. Write quick_scene quick_scene Write set_brightness Set the brightness of a light. Write set_color_preset Apply a color preset to a light. Write set_color_rgb Set light color using RGB values.

All 23 Philips Hue MCP Server tools →

Write tools on other servers

M-Team MCP Server download_torrent YouTube MCP Server generate_video_title Android Forensics ADB MCP Server combine_reports 0xarchive web3_signup

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Argument validation → Checking tool call arguments against schema and policy before they run.
Scoped token → Per-person credentials that grant a defined subset of servers and tools.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about turn_on_light

What does the turn_on_light tool do? +

Turn on a specific light by ID. It is categorised as a Write tool in the Philips Hue MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on turn_on_light? +

Register the Philips Hue MCP Server MCP server in PolicyLayer and add a rule for turn_on_light: 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 Philips Hue MCP Server. Nothing to install.

What risk level is turn_on_light? +

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

Can I rate-limit turn_on_light? +

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

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

turn_on_light is provided by the Philips Hue MCP Server MCP server (thomasrohde/hue-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Philips Hue MCP Server tool call.

Start from Philips Hue MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →