set_mesh_surface_material · Godot MCP: Risk & Policy

WHAT IT DOES

What set_mesh_surface_material does on Godot

AI agents use set_mesh_surface_material to create or update resources in Godot — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Godot environment.

PARAMETERS

Parameter	Type	Required	Description
`node_name`	string	Yes	MeshInstance node name
`scene_path`	string	Yes	Path to .tscn scene
`material_path`	string	Yes	Path to material .tres file
`surface_index`	object	—	Surface index

Parameters from the server's own tool schema.

WHY IT NEEDS A POLICY

Why set_mesh_surface_material needs a policy

This tool modifies rendering properties of a mesh in the Godot game engine by updating its surface material. While this changes game state, it is reversible (materials can be changed back or reassigned), so it falls under Write rather than Destructive.

From the tool's definition Tool description states 'Set surface material on MeshInstance', which modifies a property of a game object. The verb 'set' indicates a reversible modification operation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

set_mesh_surface_material Rate-limited

set_mesh_surface_material 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.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "set_mesh_surface_material": {
      "limits": [
        {
          "counter": "set_mesh_surface_material_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about set_mesh_surface_material

What does the set_mesh_surface_material tool do? +

Set surface material on MeshInstance. It is categorised as a Write tool in the Godot MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

What parameters does set_mesh_surface_material accept? +

set_mesh_surface_material accepts 4 parameters: node_name, scene_path, material_path, surface_index. Required: node_name, scene_path, material_path. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on set_mesh_surface_material? +

Register the Godot MCP server in PolicyLayer and add a rule for set_mesh_surface_material: 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 Godot. Nothing to install.

What risk level is set_mesh_surface_material? +

set_mesh_surface_material is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit set_mesh_surface_material? +

Yes. Add a rate_limit block to the set_mesh_surface_material 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 set_mesh_surface_material completely? +

Set action: deny in the PolicyLayer policy for set_mesh_surface_material. 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 set_mesh_surface_material? +

set_mesh_surface_material is provided by the Godot MCP server (@yanhuifair/godot-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.