set_colour · Zencontrol Cloud MCP: Risk & Policy

WHAT IT DOES

What set_colour does on Zencontrol Cloud

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

WHY IT NEEDS A POLICY

Why set_colour needs a policy

This tool creates or modifies lighting system state (color settings) reversibly. It does not delete data (Destructive), execute arbitrary code (Execute), or move money (Financial). While empty description reduces confidence slightly, the name and context of a lighting control system clearly indicate Write category.

From the tool's definition Tool name 'set_colour' indicates modification of light color properties in a DALI-2 lighting control system. Sibling tools like 'control_light' and 'get_live_light_levels' confirm this is a control/write interface for physical lighting systems.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

set_colour Rate-limited

set_colour 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_colour": {
      "limits": [
        {
          "counter": "set_colour_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 Zencontrol Cloud, so you can run agents against it safely.

FAQ

Questions about set_colour

What does the set_colour tool do? +

set_colour. It is categorised as a Write tool in the Zencontrol Cloud 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_colour? +

Register the Zencontrol Cloud MCP server in PolicyLayer and add a rule for set_colour: 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 Zencontrol Cloud. Nothing to install.

What risk level is set_colour? +

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

Can I rate-limit set_colour? +

Yes. Add a rate_limit block to the set_colour 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_colour completely? +

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

set_colour is provided by the Zencontrol Cloud MCP server (owretch/zencontrol-cloud-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.