AI agents invoke move_avatar to trigger actions in VRChat MCP OSC. 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.
This tool triggers an external operation (movement) in a live VRChat environment. It doesn't merely read or write data, but actively controls avatar behavior in real-time VR. Misuse could cause disruptive or unintended in-world behavior, but blast radius is limited to the virtual environment.
From the tool's definition Move the avatar in a specific direction
Documented attack patterns abuse exactly the kind of access move_avatar gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and VRChat MCP OSC, and nothing reaches the server without passing your rules. This is the rule we recommend for move_avatar:
{
"version": "1",
"default": "deny",
"tools": {
"move_avatar": {
"limits": [
{
"counter": "move_avatar_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}move_avatar 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.
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Move the avatar in a specific direction. It is categorised as a Execute tool in the VRChat MCP OSC MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the VRChat MCP OSC MCP server in PolicyLayer and add a rule for move_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 VRChat MCP OSC. Nothing to install.
move_avatar 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 move_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 move_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.
move_avatar is provided by the VRChat MCP OSC MCP server (krekun/vrchat-mcp-osc). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from VRChat MCP OSC, 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.
12 VRChat MCP OSC tools catalogued and risk-classified — across an index of 43,000+ MCP servers.