# add_statetree_evaluator

A write tool on the Unreal-MCP MCP server.

Agent View of the PolicyLayer registry record for `add_statetree_evaluator`. HTML page: https://policylayer.com/tools/aadeshrao123-unreal-mcp/add-statetree-evaluator

## Facts

- Tool: `add_statetree_evaluator`
- Server: Unreal-MCP (`aadeshrao123/unreal-mcp`) — https://policylayer.com/tools/aadeshrao123-unreal-mcp.md
- Homepage: https://github.com/aadeshrao123/Unreal-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": "add_statetree_evaluator",
    "arguments": {}
  }
}
```

## Why add_statetree_evaluator is rated Medium

The tool performs a create/modify operation ('add_') on StateTree evaluators within the Unreal Editor. This is a Write action as it introduces new editor content that can be subsequently modified or removed. The empty description reduces confidence slightly, but the naming pattern and server context clearly indicate asset creation rather than deletion, execution, or data retrieval.

From the tool's own definition: "Tool name 'add_statetree_evaluator' indicates adding/creating a component in Unreal Engine's StateTree system. The 'add_' prefix and context of 280 editor commands across blueprints, materials, and VFX suggest this creates or modifies editor assets reversibly."

## Use case

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

## Recommended policy (PolicyLayer)

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

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

## Other tools on Unreal-MCP (285)

- `cleanup_material_function` — Destructive — https://policylayer.com/tools/aadeshrao123-unreal-mcp/cleanup-material-function.md
- `cleanup_material_graph` — Destructive — https://policylayer.com/tools/aadeshrao123-unreal-mcp/cleanup-material-graph.md
- `clear_niagara_module_input` — Destructive — https://policylayer.com/tools/aadeshrao123-unreal-mcp/clear-niagara-module-input.md
- `delete_actor` — Destructive — https://policylayer.com/tools/aadeshrao123-unreal-mcp/delete-actor.md
- `delete_asset` — Destructive — https://policylayer.com/tools/aadeshrao123-unreal-mcp/delete-asset.md
- `delete_blueprint_function` — Destructive — https://policylayer.com/tools/aadeshrao123-unreal-mcp/delete-blueprint-function.md
- `delete_blueprint_node` — Destructive — https://policylayer.com/tools/aadeshrao123-unreal-mcp/delete-blueprint-node.md
- `delete_data_table_row` — Destructive — https://policylayer.com/tools/aadeshrao123-unreal-mcp/delete-data-table-row.md
- `delete_material_expression` — Destructive — https://policylayer.com/tools/aadeshrao123-unreal-mcp/delete-material-expression.md
- `delete_niagara_graph_node` — Destructive — https://policylayer.com/tools/aadeshrao123-unreal-mcp/delete-niagara-graph-node.md
- `delete_niagara_scratch_pad_module` — Destructive — https://policylayer.com/tools/aadeshrao123-unreal-mcp/delete-niagara-scratch-pad-module.md
- `delete_niagara_system` — Destructive — https://policylayer.com/tools/aadeshrao123-unreal-mcp/delete-niagara-system.md
- `remove_input_action_modifier` — Destructive — https://policylayer.com/tools/aadeshrao123-unreal-mcp/remove-input-action-modifier.md
- `remove_input_action_trigger` — Destructive — https://policylayer.com/tools/aadeshrao123-unreal-mcp/remove-input-action-trigger.md
- `remove_key_mapping` — Destructive — https://policylayer.com/tools/aadeshrao123-unreal-mcp/remove-key-mapping.md
- `remove_mapping_modifier` — Destructive — https://policylayer.com/tools/aadeshrao123-unreal-mcp/remove-mapping-modifier.md
- `remove_mapping_trigger` — Destructive — https://policylayer.com/tools/aadeshrao123-unreal-mcp/remove-mapping-trigger.md
- `remove_mass_config_trait` — Destructive — https://policylayer.com/tools/aadeshrao123-unreal-mcp/remove-mass-config-trait.md
- `remove_niagara_custom_hlsl_pin` — Destructive — https://policylayer.com/tools/aadeshrao123-unreal-mcp/remove-niagara-custom-hlsl-pin.md
- `remove_niagara_emitter` — Destructive — https://policylayer.com/tools/aadeshrao123-unreal-mcp/remove-niagara-emitter.md
- `remove_niagara_module` — Destructive — https://policylayer.com/tools/aadeshrao123-unreal-mcp/remove-niagara-module.md
- `remove_niagara_node_pin` — Destructive — https://policylayer.com/tools/aadeshrao123-unreal-mcp/remove-niagara-node-pin.md
- `remove_niagara_renderer` — Destructive — https://policylayer.com/tools/aadeshrao123-unreal-mcp/remove-niagara-renderer.md
- `remove_niagara_script_parameter` — Destructive — https://policylayer.com/tools/aadeshrao123-unreal-mcp/remove-niagara-script-parameter.md
- `remove_niagara_user_parameter` — Destructive — https://policylayer.com/tools/aadeshrao123-unreal-mcp/remove-niagara-user-parameter.md
- `remove_statetree_binding` — Destructive — https://policylayer.com/tools/aadeshrao123-unreal-mcp/remove-statetree-binding.md
- `remove_statetree_node` — Destructive — https://policylayer.com/tools/aadeshrao123-unreal-mcp/remove-statetree-node.md
- `remove_statetree_parameter` — Destructive — https://policylayer.com/tools/aadeshrao123-unreal-mcp/remove-statetree-parameter.md
- `remove_statetree_state` — Destructive — https://policylayer.com/tools/aadeshrao123-unreal-mcp/remove-statetree-state.md
- `remove_statetree_transition` — Destructive — https://policylayer.com/tools/aadeshrao123-unreal-mcp/remove-statetree-transition.md
- …and 255 more: https://policylayer.com/tools/aadeshrao123-unreal-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=aadeshrao123-unreal-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/aadeshrao123-unreal-mcp