Remove a source from a knowledge base.
AI agents call retell_delete_knowledge_base_source to permanently remove resources in Retell AI MCP Server — typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.
This tool irreversibly deletes/removes data (a knowledge base source) that cannot be easily recovered. It is a destructive operation with no undo capability. The severity is high because removing knowledge base sources could disrupt AI agent functionality, degrade conversation quality, or cause loss of important training data, depending on the business context.
From the tool's definition The tool is named 'retell_delete_knowledge_base_source' with description 'Remove a source from a knowledge base.' The verb 'delete' and 'remove' directly indicate irreversible data removal.
Attacks that exploit this kind of access
Remove a source from a knowledge base. It is categorised as a Destructive tool in the Retell AI MCP Server MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.
Register the Retell AI MCP Server MCP server in PolicyLayer and add a rule for retell_delete_knowledge_base_source: 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 Retell AI MCP Server. Nothing to install.
retell_delete_knowledge_base_source 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 retell_delete_knowledge_base_source 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 retell_delete_knowledge_base_source. 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.
retell_delete_knowledge_base_source is provided by the Retell AI MCP Server MCP server (itsanamune/retellsimp). 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.
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