Cancel a specific open order by ID.
AI agents call cancel_order to permanently remove resources in Polymarket MCP Server — typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.
Cancelling an order is an irreversible action that permanently removes a live market order. Once cancelled, the order cannot be reinstated — a new order would have to be created, potentially at a different price or market condition. In a financial trading context, this is effectively irreversible (the original order slot, price, and queue position are lost), making it Destructive rather than merely Write.
From the tool's definition Cancel a specific open order by ID
Attacks that exploit this kind of access
Cancel a specific open order by ID. It is categorised as a Destructive tool in the Polymarket MCP Server MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.
Register the Polymarket MCP Server MCP server in PolicyLayer and add a rule for cancel_order: 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 Polymarket MCP Server. Nothing to install.
cancel_order is a Destructive tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.
Yes. Add a rate_limit block to the cancel_order 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 cancel_order. 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.
cancel_order is provided by the Polymarket MCP Server MCP server (nancheng582-jpg/polymarket-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
Teams ship this data inside their own products. See what a licence covers →