Call a Home Assistant service. This is one of the most powerful endpoints, allowing you to execute actions and control devices. Services are organized by domains, which typically correspond to integrations or components. Common use cases include turning devices on or off, adjusting settings like ...
AI agents invoke tools-services-call to trigger actions in Home Assistant MCP Server. 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.
This tool executes arbitrary Home Assistant services with consequences determined by the arguments passed. While it can perform many reversible actions (turning lights on/off), it can also trigger irreversible operations (e.g., automation sequences, system operations) and has broad blast radius across smart home devices.
From the tool's definition Description states 'one of the most powerful endpoints, allowing you to execute actions and control devices' and lists capabilities including 'turning devices on or off, adjusting settings like brightness, temperature, or volume, triggering automations or…
Attacks that exploit this kind of access
Call a Home Assistant service. This is one of the most powerful endpoints, allowing you to execute actions and control devices. Services are organized by domains, which typically correspond to integrations or components. Common use cases include turning devices on or off, adjusting settings like brightness, temperature, or volume, triggering automations or scenes, and running system operations. It is categorised as a Execute tool in the Home Assistant MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Home Assistant MCP Server MCP server in PolicyLayer and add a rule for tools-services-call: 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 Assistant MCP Server. Nothing to install.
tools-services-call is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the tools-services-call 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 tools-services-call. 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.
tools-services-call is provided by the Home Assistant MCP Server MCP server (oleander/home-assistant-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
Teams ship this data inside their own products. See what a licence covers →