spawn_niagara_at_location
Spawn a Niagara particle system at a world location.
This record as markdown: /tools/jjpxdev-unreal-mcp/spawn-niagara-at-location.md
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.
| Parameter | Type | Required | Description |
|---|---|---|---|
location | object | Yes | World location |
rotation | object | — | |
system_path | string | Yes | Niagara system asset path |
auto_destroy | boolean | — | Auto-destroy when finished |
Parameters from the server's own tool schema.
Why spawn_niagara_at_location is rated High
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
Risk signalsHigh parameter count (10 properties)
Attacks that exploit this kind of access
The rule that runs spawn_niagara_at_location 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 spawn_niagara_at_location, this is the rule to start with:
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.
The button opens the PolicyLayer dashboard: create your workspace, connect Unreal, apply this rule, and every spawn_niagara_at_location call is checked against it from then on.
Questions about spawn_niagara_at_location
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.
spawn_niagara_at_location accepts 4 parameters: location, rotation, system_path, auto_destroy. Required: location, system_path. 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 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.
spawn_niagara_at_location 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 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.
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.
spawn_niagara_at_location 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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