List all available Home Assistant devices with optional filtering by domain, area, or floor.
AI agents call list_devices to retrieve information from HomeAssistant MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves and queries device information from Home Assistant with no side effects. The filtering parameters (domain, area, floor) are all read-only operations. Classification as Read is appropriate, with low severity since it only exposes device metadata without the ability to control or modify any devices.
From the tool's definition Tool name 'list_devices' and description 'List all available Home Assistant devices' indicates a query/retrieval operation with optional filtering. No modification, deletion, execution, or financial operations are performed.
Documented attack patterns abuse exactly the kind of access list_devices gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and HomeAssistant MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for list_devices:
{
"version": "1",
"default": "deny",
"tools": {
"list_devices": {}
}
}list_devices is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
Free to start. No card required.
List all available Home Assistant devices with optional filtering by domain, area, or floor. It is categorised as a Read tool in the HomeAssistant MCP MCP Server, which means it retrieves data without modifying state.
Register the HomeAssistant MCP server in PolicyLayer and add a rule for list_devices: 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 HomeAssistant MCP. Nothing to install.
list_devices is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the list_devices 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 list_devices. 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.
list_devices is provided by the HomeAssistant MCP server (jango-blockchained/advanced-homeassistant-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from HomeAssistant MCP, 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.
13 HomeAssistant MCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.