# add_statetree_parameter

Add a tree-level parameter.

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

## Facts

- Tool: `add_statetree_parameter`
- 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_parameter",
    "arguments": {}
  }
}
```

## Why add_statetree_parameter is rated Medium

This tool creates or modifies StateTree data structures by adding parameters. It is a reversible operation (parameters can be removed or modified), placing it in the Write category rather than Destructive. The severity is medium because misuse could corrupt StateTree logic or create invalid parameter configurations, but the effect is limited to a single asset and reversible.

From the tool's own definition: "Tool name 'add_statetree_parameter' and description 'Add a tree-level parameter' indicate creation of a new parameter in a StateTree asset within Unreal Engine 5."

## Use case

AI agents use add_statetree_parameter 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_parameter": {
      "limits": [
        {
          "counter": "add_statetree_parameter_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`

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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