piece_move
Move a piece onto a board cell by id (reparent + snap via board_place), optionally with a short scale "pop" animation authored from Group C anim primitives. Undoable node authoring; purely additive — it emits only existing node / anim ops, never a new engine call. Returns the piece's new path.
This record as markdown: /tools/breakpoint-mcp/piece-move.md
What piece_move does on Breakpoint
AI agents use piece_move 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.
| Parameter | Type | Required | Description |
|---|---|---|---|
to | string | Yes | Destination cell id (resolves to <board>/cell_<to>) |
from | string | — | Source cell id, echoed in the result for the caller's convenience |
node | string | Yes | Node path of the piece to move |
align | object | — | Offset from the cell origin in px (default 0,0 — centred on the anchor) |
board | string | Yes | Board root node path in the open scene ("." if the board is the scene root) |
animate | object | — | Optional pop animation; omitted → an instant snap |
Parameters from the server's own tool schema.
Why piece_move is rated Medium
This tool creates or modifies data (piece position on board) reversibly through reparenting and animation operations. The 'Undoable' nature confirms it is Write (not Destructive). While it triggers animation operations from the sibling anim tools, the core function is state modification rather than arbitrary code execution.
From the tool's definition Tool description states it performs 'Move a piece onto a board cell' and 'reparent + snap via board_place', which modifies the state of board pieces. Described as 'Undoable node authoring; purely additive' indicating reversible modifications to game state.
Risk signalsHigh parameter count (13 properties)
Attacks that exploit this kind of access
The rule that runs piece_move safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Breakpoint, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For piece_move, this is the rule to start with:
piece_move stays usable, but capped: an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect Breakpoint, apply this rule, and every piece_move call is checked against it from then on.
Questions about piece_move
Move a piece onto a board cell by id (reparent + snap via board_place), optionally with a short scale "pop" animation authored from Group C anim primitives. Undoable node authoring; purely additive — it emits only existing node / anim ops, never a new engine call. Returns the piece's new path. It is categorised as a Write tool in the Breakpoint MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
piece_move accepts 6 parameters: to, from, node, align, board, animate. Required: to, node, board. The full parameter table on this page comes from the server's own tool schema.
Register the Breakpoint MCP server in PolicyLayer and add a rule for piece_move: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Breakpoint. Nothing to install.
piece_move is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the piece_move rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for piece_move. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
piece_move is provided by the Breakpoint MCP server (breakpoint-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
More on Breakpoint, and thousands of servers like it.
This server
Across the catalogue