# create_material_instance

A write tool on the Uefn MCP server.

Agent View of the PolicyLayer registry record for `create_material_instance`. HTML page: https://policylayer.com/tools/quangdang46-uefn-verse-mcp/create-material-instance

## Facts

- Tool: `create_material_instance`
- Server: Uefn (`quangdang46/uefn-verse-mcp`) — https://policylayer.com/tools/quangdang46-uefn-verse-mcp.md
- Homepage: https://github.com/quangdang46/uefn-verse-mcp
- Risk category: Write (Medium risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Rate-limited

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "create_material_instance",
    "arguments": {}
  }
}
```

## Why create_material_instance is rated Medium

Creating a material instance is a reversible write operation that modifies editor assets. It does not execute arbitrary code, delete data irreversibly, or move money. The blast radius is medium because incorrect material instance creation could affect visual presentation of many actors, but changes can be undone in the editor.

From the tool's own definition: "Tool name 'create_material_instance' indicates creation of a new material instance in UEFN editor. Sibling tools like 'actor_move_to_folder', 'actor_set_label', and 'audio_place' confirm this server performs reversible modifications to editor state."

## Use case

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

## Recommended policy (PolicyLayer)

Verdict: **Rate-limited**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Uefn:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "create_material_instance": {
      "limits": [
        {
          "counter": "create_material_instance_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## Other tools on Uefn (142)

- `delete_actors` — Destructive — https://policylayer.com/tools/quangdang46-uefn-verse-mcp/delete-actors.md
- `delete_asset` — Destructive — https://policylayer.com/tools/quangdang46-uefn-verse-mcp/delete-asset.md
- `shutdown` — Destructive — https://policylayer.com/tools/quangdang46-uefn-verse-mcp/shutdown.md
- `snapshot_restore` — Destructive — https://policylayer.com/tools/quangdang46-uefn-verse-mcp/snapshot-restore.md
- `tag_remove` — Destructive — https://policylayer.com/tools/quangdang46-uefn-verse-mcp/tag-remove.md
- `undo` — Destructive — https://policylayer.com/tools/quangdang46-uefn-verse-mcp/undo.md
- `batch_exec` — Execute — https://policylayer.com/tools/quangdang46-uefn-verse-mcp/batch-exec.md
- `blueprint_compile` — Execute — https://policylayer.com/tools/quangdang46-uefn-verse-mcp/blueprint-compile.md
- `bulk_mirror` — Execute — https://policylayer.com/tools/quangdang46-uefn-verse-mcp/bulk-mirror.md
- `device_call_method` — Execute — https://policylayer.com/tools/quangdang46-uefn-verse-mcp/device-call-method.md
- `device_sim_generate_proxy` — Execute — https://policylayer.com/tools/quangdang46-uefn-verse-mcp/device-sim-generate-proxy.md
- `device_sim_trigger_method` — Execute — https://policylayer.com/tools/quangdang46-uefn-verse-mcp/device-sim-trigger-method.md
- `execute_python` — Execute — https://policylayer.com/tools/quangdang46-uefn-verse-mcp/execute-python.md
- `focus_selected` — Execute — https://policylayer.com/tools/quangdang46-uefn-verse-mcp/focus-selected.md
- `niagara_spawn_system` — Execute — https://policylayer.com/tools/quangdang46-uefn-verse-mcp/niagara-spawn-system.md
- `postprocess_spawn` — Execute — https://policylayer.com/tools/quangdang46-uefn-verse-mcp/postprocess-spawn.md
- `refresh_device_catalog` — Execute — https://policylayer.com/tools/quangdang46-uefn-verse-mcp/refresh-device-catalog.md
- `run_tool` — Execute — https://policylayer.com/tools/quangdang46-uefn-verse-mcp/run-tool.md
- `scatter_along_spline` — Execute — https://policylayer.com/tools/quangdang46-uefn-verse-mcp/scatter-along-spline.md
- `scatter_props` — Execute — https://policylayer.com/tools/quangdang46-uefn-verse-mcp/scatter-props.md
- `select_actors` — Execute — https://policylayer.com/tools/quangdang46-uefn-verse-mcp/select-actors.md
- `select_by_class` — Execute — https://policylayer.com/tools/quangdang46-uefn-verse-mcp/select-by-class.md
- `sign_spawn_bulk` — Execute — https://policylayer.com/tools/quangdang46-uefn-verse-mcp/sign-spawn-bulk.md
- `smart_spawn` — Execute — https://policylayer.com/tools/quangdang46-uefn-verse-mcp/smart-spawn.md
- `verse_build` — Execute — https://policylayer.com/tools/quangdang46-uefn-verse-mcp/verse-build.md
- `verse_template_deploy` — Execute — https://policylayer.com/tools/quangdang46-uefn-verse-mcp/verse-template-deploy.md
- `zone_spawn` — Execute — https://policylayer.com/tools/quangdang46-uefn-verse-mcp/zone-spawn.md
- `bulk_randomize` — Other — https://policylayer.com/tools/quangdang46-uefn-verse-mcp/bulk-randomize.md
- `pattern_circle` — Other — https://policylayer.com/tools/quangdang46-uefn-verse-mcp/pattern-circle.md
- `pattern_grid` — Other — https://policylayer.com/tools/quangdang46-uefn-verse-mcp/pattern-grid.md
- …and 112 more: https://policylayer.com/tools/quangdang46-uefn-verse-mcp.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=quangdang46-uefn-verse-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/quangdang46-uefn-verse-mcp