[WRITE] Update existing automation in Home Assistant. MODIFIES configuration - requires approval. Provide a meaningful description of what changed and why (e.g.,
Part of the Home Assistant server.
Free to start. No card required.
AI agents use ha_update_automation to create or modify resources in Home Assistant. Write operations carry medium risk because an autonomous agent could trigger bulk unintended modifications. Rate limits prevent a single agent session from making hundreds of changes in rapid succession. Argument validation ensures the agent passes expected values.
Without a policy, an AI agent could call ha_update_automation repeatedly, creating or modifying resources faster than any human could review. PolicyLayer's rate limiting ensures write operations happen at a controlled pace, and argument validation catches malformed or unexpected inputs before they reach Home Assistant.
Write tools can modify data. A rate limit prevents runaway bulk operations from AI agents.
{
"version": "1",
"default": "deny",
"tools": {
"ha_update_automation": {
"limits": [
{
"counter": "ha_update_automation_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}See the full Home Assistant policy for all 96 tools.
These attack patterns abuse exactly the kind of access ha_update_automation gives an agent. Each links to the full case and the policy that stops it:
Other write tools across the catalogue. The same approach applies to each: rate-limit and validate the arguments.
[WRITE] Update existing automation in Home Assistant. MODIFIES configuration - requires approval. Provide a meaningful description of what changed and why (e.g.,. It is categorised as a Write tool in the Home Assistant MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Home Assistant MCP server in PolicyLayer and add a rule for ha_update_automation: 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. Nothing to install.
ha_update_automation 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 ha_update_automation 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 ha_update_automation. 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.
ha_update_automation is provided by the Home Assistant MCP server (@coolver/home-assistant-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 96 Home Assistant tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
4,600+ MCP servers and 31,000+ tools scanned and risk-classified.