Delete a relation by ID.
AI agents call relation_delete to permanently remove resources in Mementos — typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.
This tool irreversibly removes data (a relation) from the memory system. Deletion operations are classified as Destructive per the schema rules. The severity is high because misuse by an AI agent could remove important relationships between entities in the agent's memory, potentially corrupting its knowledge state or decision-making capabilities.
From the tool's definition Tool name is 'relation_delete' and description states 'Delete a relation by ID.' The verb 'delete' combined with the irreversible nature of removing a relation from a memory system indicates this is a destructive operation that cannot be undone.
Attacks that exploit this kind of access
Delete a relation by ID. It is categorised as a Destructive tool in the Mementos MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.
Register the Mementos MCP server in PolicyLayer and add a rule for relation_delete: 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 Mementos. Nothing to install.
relation_delete 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 relation_delete 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 relation_delete. 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.
relation_delete is provided by the Mementos MCP server (@hasna/mementos). 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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