Drop index and remove all cached data for a directory.
AI agents call knowledge_drop_index to permanently remove resources in XLMCP — typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.
An AI agent that decides to call knowledge_drop_index doesn't hesitate, doesn't double-check, and doesn't stop at one. Whatever it removes from XLMCP is gone — there is no undo for destructive operations.
Attacks that exploit this kind of access
Drop index and remove all cached data for a directory. It is categorised as a Destructive tool in the XLMCP MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.
Register the XL MCP server in PolicyLayer and add a rule for knowledge_drop_index: 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 XLMCP. Nothing to install.
knowledge_drop_index 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 knowledge_drop_index 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 knowledge_drop_index. 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.
knowledge_drop_index is provided by the XL MCP server (xlydiansoftware/aix). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.