Materialize an animated agent avatar in the 3D scene.
AI agents use spawn_agent_avatar to create or update resources in Worldlabs — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Worldlabs environment.
The tool creates/adds a new entity (avatar) into a 3D scene, which is a reversible write/create operation. There is no indication of deletion, code execution, or financial transactions. Severity is medium because spawning an avatar in a shared 3D world could affect other users' experiences, but it appears to be a standard scene mutation.
From the tool's definition Materialize an animated agent avatar in the 3D scene
Documented attack patterns abuse exactly the kind of access spawn_agent_avatar gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Worldlabs, and nothing reaches the server without passing your rules. This is the rule we recommend for spawn_agent_avatar:
{
"version": "1",
"default": "deny",
"tools": {
"spawn_agent_avatar": {
"limits": [
{
"counter": "spawn_agent_avatar_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}spawn_agent_avatar 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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Materialize an animated agent avatar in the 3D scene. It is categorised as a Write tool in the Worldlabs MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Worldlabs MCP server in PolicyLayer and add a rule for spawn_agent_avatar: 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 Worldlabs. Nothing to install.
spawn_agent_avatar 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 spawn_agent_avatar 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_agent_avatar. 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_agent_avatar is provided by the Worldlabs MCP server (sandraschi/worldlabs-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Worldlabs, 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.
20 Worldlabs tools catalogued and risk-classified — across an index of 43,000+ MCP servers.