call_preset_function
Call a function exposed via a Remote Control Preset.
This record as markdown: /tools/jjpxdev-unreal-mcp/call-preset-function.md
What call_preset_function does on Unreal
AI agents invoke call_preset_function to trigger actions in Unreal. 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.
| Parameter | Type | Required | Description |
|---|---|---|---|
parameters | object | — | Function parameters |
preset_name | string | Yes | Preset name |
function_name | string | Yes | Exposed function name |
Parameters from the server's own tool schema.
Why call_preset_function is rated High
This tool executes functions exposed through Unreal Engine's Remote Control Preset system. Since it calls arbitrary functions, the effects are entirely dependent on what function is invoked — could range from benign reads to destructive operations. The most severe applicable category is Execute, as it triggers external operations whose effects depend on arguments.
From the tool's definition "Call a function exposed via a Remote Control Preset"
Attacks that exploit this kind of access
The rule that runs call_preset_function safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Unreal, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For call_preset_function, this is the rule to start with:
call_preset_function stays usable, but rate-capped: a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect Unreal, apply this rule, and every call_preset_function call is checked against it from then on.
Questions about call_preset_function
Call a function exposed via a Remote Control Preset. It is categorised as a Execute tool in the Unreal MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
call_preset_function accepts 3 parameters: parameters, preset_name, function_name. Required: preset_name, function_name. The full parameter table on this page comes from the server's own tool schema.
Register the Unreal MCP server in PolicyLayer and add a rule for call_preset_function: 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 Unreal. Nothing to install.
call_preset_function 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 call_preset_function 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 call_preset_function. 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.
call_preset_function is provided by the Unreal MCP server (@jjpxdev/unreal-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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