# piece_instance

Instance a piece template into the open scene and bind data (art / color / label) via the template's set_data(). Undoable node authoring. Optionally place_on a board cell in the same call (reparent + snap via board_place). Reports which data keys bound and which had no matching slot.

Agent View of the PolicyLayer registry record for `piece_instance`. HTML page: https://policylayer.com/tools/breakpoint-mcp/piece-instance

## Facts

- Tool: `piece_instance`
- 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: 8 (3 required)
- Recommended policy verdict: Rate-limited

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `data` | object | yes | Slot name → value (art takes a res:// path; color a #RRGGBB; label a string) |
| `name` | string | no | Optional node name for the instance |
| `parent` | string | yes | Node path to parent the instance under (in the open scene); "." for the root |
| `face_up` | boolean | no | Show the face (default true); false shows the back on two-sided pieces |
| `persist` | boolean | no | Bake the bound data into the saved scene by enabling Editable Children on the instance (default false = runtime-bound only, reverts on reload) |
| `place_on` | object | no | Optionally place the new piece on a board cell in the same call |
| `position` | object | no | Local position of the instance (ignored when place_on snaps it to a cell) |
| `template_path` | string | yes | Piece template scene, e.g. res://ui/pieces/Piece.tscn |

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": "piece_instance",
    "arguments": {
      "data": {},
      "parent": "<parent>",
      "template_path": "<template_path>"
    }
  }
}
```

## Why piece_instance is rated Medium

This tool creates new instances and modifies scene state by binding data to templates. These are creation and modification operations without permanent destruction. The reversibility ("Undoable") and the fact that it operates within a scene authoring context (likely a game or animation editor) place it in the Write category.

From the tool's own definition: "The tool 'instances a piece template into the open scene and bind data' and is described as 'Undoable node authoring.' It creates new scene objects and modifies data bindings, which are Write operations."

Risk signals: High parameter count (15 properties)

## Use case

AI agents use piece_instance 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": {
    "piece_instance": {
      "limits": [
        {
          "counter": "piece_instance_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