device_set_property
AI agents use device_set_property to create or update resources in Uefn — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Uefn environment.
The tool appears to modify device properties reversibly without deleting data or executing arbitrary code. Classified as Write rather than Execute because property-setting operations typically change configuration state rather than trigger external processes or shell commands.
From the tool's definition Tool name 'device_set_property' indicates modification of device properties. No description provided, but the naming pattern and context within a UEFN editor (Unreal Editor for Fortnite) bridge suggests this sets properties on in-editor objects.
Documented attack patterns abuse exactly the kind of access device_set_property gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Uefn, and nothing reaches the server without passing your rules. This is the rule we recommend for device_set_property:
{
"version": "1",
"default": "deny",
"tools": {
"device_set_property": {
"limits": [
{
"counter": "device_set_property_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}device_set_property 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.
Free to start. No card required.
device_set_property. It is categorised as a Write tool in the Uefn MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Uefn MCP server in PolicyLayer and add a rule for device_set_property: 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 Uefn. Nothing to install.
device_set_property 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 device_set_property 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 device_set_property. 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.
device_set_property is provided by the Uefn MCP server (quangdang46/uefn-verse-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Uefn, 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.
143 Uefn tools catalogued and risk-classified — across an index of 43,000+ MCP servers.