AI agents use verse_write_file 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.
File writing is a reversible modification operation (Write category). Severity is high because unauthorized file writes in a live editor could corrupt project state, introduce malicious code into game logic, or disrupt development workflows. The empty description lowers confidence slightly, but the name is unambiguous enough to justify high confidence.
From the tool's definition Tool name 'verse_write_file' indicates file writing capability. Description is empty, but the name strongly suggests creating or modifying files in the UEFN (Unreal Editor for Fortnite) environment.
Documented attack patterns abuse exactly the kind of access verse_write_file 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 verse_write_file:
{
"version": "1",
"default": "deny",
"tools": {
"verse_write_file": {
"limits": [
{
"counter": "verse_write_file_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}verse_write_file 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.
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verse_write_file. 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 verse_write_file: 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.
verse_write_file 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 verse_write_file 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 verse_write_file. 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.
verse_write_file 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.