# container_add_child

Instance a Control-derived child under a Container node (VBoxContainer, GridContainer, MarginContainer, …) so it participates in the container's layout (undoable). Refuses a non-Container parent or a non-Control child. Returns the new node's path.

Agent View of the PolicyLayer registry record for `container_add_child`. HTML page: https://policylayer.com/tools/breakpoint-mcp/container-add-child

## Facts

- Tool: `container_add_child`
- Server: Breakpoint (`breakpoint-mcp`) — https://policylayer.com/tools/breakpoint-mcp.md
- Install: `npx -y breakpoint-mcp`
- Homepage: https://www.npmjs.com/package/breakpoint-mcp
- Risk category: Write (Medium risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 3 (2 required)
- Recommended policy verdict: Rate-limited

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `name` | string | no | Node name (defaults to the class name) |
| `type` | string | yes | Control subclass to instance as the container's child, e.g. Button, Label |
| `container_path` | string | yes | Container node path relative to the scene root |

Parameters from the server's own tool schema.

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

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "container_add_child",
    "arguments": {
      "type": "<type>",
      "container_path": "<container_path>"
    }
  }
}
```

## Why container_add_child is rated Medium

This tool creates/instantiates new UI nodes within a scene hierarchy. It is a Write operation because it creates data structures (scene nodes) that can be reversed via undo. The blast radius is medium—improper instantiation could clutter the scene tree or create unexpected UI layouts, but the undoable nature and containment within a UI framework limits severity.

From the tool's own definition: "Tool creates a new child node under a Container: 'Instance a Control-derived child under a Container node', 'Returns the new node's path'. The operation is explicitly marked as 'undoable', confirming it modifies the scene tree reversibly."

## Use case

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

## Recommended policy (PolicyLayer)

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

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

## Other tools on Breakpoint (273)

- `anim_delete` — Destructive — https://policylayer.com/tools/breakpoint-mcp/anim-delete.md
- `anim_remove_key` — Destructive — https://policylayer.com/tools/breakpoint-mcp/anim-remove-key.md
- `filesystem_move` — Destructive — https://policylayer.com/tools/breakpoint-mcp/filesystem-move.md
- `gd_rename` — Destructive — https://policylayer.com/tools/breakpoint-mcp/gd-rename.md
- `inputmap_erase_action` — Destructive — https://policylayer.com/tools/breakpoint-mcp/inputmap-erase-action.md
- `mp_wire_rpc` — Destructive — https://policylayer.com/tools/breakpoint-mcp/mp-wire-rpc.md
- `node_delete` — Destructive — https://policylayer.com/tools/breakpoint-mcp/node-delete.md
- `project_remove_autoload` — Destructive — https://policylayer.com/tools/breakpoint-mcp/project-remove-autoload.md
- `resource_save` — Destructive — https://policylayer.com/tools/breakpoint-mcp/resource-save.md
- `resource_set_import_settings` — Destructive — https://policylayer.com/tools/breakpoint-mcp/resource-set-import-settings.md
- `runtime_node_remove` — Destructive — https://policylayer.com/tools/breakpoint-mcp/runtime-node-remove.md
- `runtime_peer_stop` — Destructive — https://policylayer.com/tools/breakpoint-mcp/runtime-peer-stop.md
- `scene_close` — Destructive — https://policylayer.com/tools/breakpoint-mcp/scene-close.md
- `scene_reload` — Destructive — https://policylayer.com/tools/breakpoint-mcp/scene-reload.md
- `shader_set_code` — Destructive — https://policylayer.com/tools/breakpoint-mcp/shader-set-code.md
- `tilemap_clear` — Destructive — https://policylayer.com/tools/breakpoint-mcp/tilemap-clear.md
- `vcs_restore` — Destructive — https://policylayer.com/tools/breakpoint-mcp/vcs-restore.md
- `vcs_stash` — Destructive — https://policylayer.com/tools/breakpoint-mcp/vcs-stash.md
- `cs_dbg_attach` — Execute — https://policylayer.com/tools/breakpoint-mcp/cs-dbg-attach.md
- `cs_dbg_continue` — Execute — https://policylayer.com/tools/breakpoint-mcp/cs-dbg-continue.md
- `cs_dbg_launch` — Execute — https://policylayer.com/tools/breakpoint-mcp/cs-dbg-launch.md
- `cs_dbg_restart` — Execute — https://policylayer.com/tools/breakpoint-mcp/cs-dbg-restart.md
- `cs_dbg_set_breakpoints` — Execute — https://policylayer.com/tools/breakpoint-mcp/cs-dbg-set-breakpoints.md
- `cs_dbg_set_exception_breakpoints` — Execute — https://policylayer.com/tools/breakpoint-mcp/cs-dbg-set-exception-breakpoints.md
- `cs_dbg_set_variable` — Execute — https://policylayer.com/tools/breakpoint-mcp/cs-dbg-set-variable.md
- `cs_dbg_step` — Execute — https://policylayer.com/tools/breakpoint-mcp/cs-dbg-step.md
- `dbg_attach` — Execute — https://policylayer.com/tools/breakpoint-mcp/dbg-attach.md
- `dbg_continue` — Execute — https://policylayer.com/tools/breakpoint-mcp/dbg-continue.md
- `dbg_data_breakpoints` — Execute — https://policylayer.com/tools/breakpoint-mcp/dbg-data-breakpoints.md
- `dbg_goto` — Execute — https://policylayer.com/tools/breakpoint-mcp/dbg-goto.md
- …and 243 more: https://policylayer.com/tools/breakpoint-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=breakpoint-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/breakpoint-mcp