AI agents use sign_set_text 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.
This tool creates or modifies text data on a sign asset, which is a reversible write operation typical of content creation in a game editor. No deletion, execution of arbitrary code, or financial impact. Severity is medium because modifying game assets could affect intended creative content, but changes are easily undoable via undo/revert in the editor.
From the tool's definition Tool name 'sign_set_text' indicates modification of text content on a sign object in UEFN. The 'set' verb and context within a Fortnite editor environment suggests updating existing sign data.
Documented attack patterns abuse exactly the kind of access sign_set_text 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 sign_set_text:
{
"version": "1",
"default": "deny",
"tools": {
"sign_set_text": {
"limits": [
{
"counter": "sign_set_text_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}sign_set_text 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.
sign_set_text. 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 sign_set_text: 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.
sign_set_text 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 sign_set_text 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 sign_set_text. 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.
sign_set_text 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.