Set the brightness of all lights in a group.
AI agents use set_group_brightness to create or update resources in Philips Hue MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Philips Hue MCP Server environment.
This tool modifies smart light settings (brightness levels) but does so reversibly. It does not delete, destroy, execute arbitrary code, move money, or trigger external operations beyond the smart lighting system itself. The blast radius is limited to cosmetic changes in a smart home lighting system.
From the tool's definition Tool name 'set_group_brightness' and description 'Set the brightness of all lights in a group' indicate the tool modifies light properties.
Documented attack patterns abuse exactly the kind of access set_group_brightness gives an agent:
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 set_group_brightness:
{
"version": "1",
"default": "deny",
"tools": {
"set_group_brightness": {
"limits": [
{
"counter": "set_group_brightness_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}set_group_brightness 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.
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Set the brightness of all lights in a group. 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.
Register the Philips Hue MCP Server MCP server in PolicyLayer and add a rule for set_group_brightness: 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.
set_group_brightness is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the set_group_brightness 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.
Set action: deny in the PolicyLayer policy for set_group_brightness. 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.
set_group_brightness 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.
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.
Free to start. No card required.
23 Philips Hue MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.