spawn_niagara_at_location · Unreal MCP: Risk & Policy

WHAT IT DOES

What spawn_niagara_at_location does on Unreal

AI agents invoke spawn_niagara_at_location 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.

WHY IT NEEDS A POLICY

Why spawn_niagara_at_location needs a policy

This tool triggers an external operation in the Unreal Engine runtime by spawning a particle system at a specified world location. It initiates an active engine operation with real-time effects, placing it in the Execute category. Misuse could clutter scenes or cause performance issues, but effects are generally transient and reversible, warranting medium severity.

From the tool's definition Spawn a Niagara particle system at a world location

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

spawn_niagara_at_location Rate-limited

spawn_niagara_at_location 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.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "spawn_niagara_at_location": {
      "limits": [
        {
          "counter": "spawn_niagara_at_location_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Unreal, so you can run agents against it safely.

FAQ

Questions about spawn_niagara_at_location

What does the spawn_niagara_at_location tool do? +

Spawn a Niagara particle system at a world location. 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.

How do I enforce a policy on spawn_niagara_at_location? +

Register the Unreal MCP server in PolicyLayer and add a rule for spawn_niagara_at_location: 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.

What risk level is spawn_niagara_at_location? +

spawn_niagara_at_location is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit spawn_niagara_at_location? +

Yes. Add a rate_limit block to the spawn_niagara_at_location 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.

How do I block spawn_niagara_at_location completely? +

Set action: deny in the PolicyLayer policy for spawn_niagara_at_location. 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.

What MCP server provides spawn_niagara_at_location? +

spawn_niagara_at_location is provided by the Unreal MCP server (sam-david/unreal-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.