delete_relations

THE RISK

Critical Risk

An AI agent that decides to call delete_relations doesn't hesitate, doesn't double-check, and doesn't stop at one. Whatever it removes from Obsidian Memory MCP is gone — there is no undo for destructive operations.

Documented attack patterns abuse exactly the kind of access delete_relations gives an agent:

HOW TO CONTROL DELETE_RELATIONS

PolicyLayer is an MCP gateway — it sits between your AI agents and Obsidian Memory MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for delete_relations:

policy.json

{
  "version": "1",
  "default": "deny",
  "hide": [
    "delete_relations"
  ]
}

delete_relations disappears from the agent's tool list entirely, and any attempt to call it is denied. The rest of the server keeps working.

Create a free account and register Obsidian Memory MCP — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

RESTRICT THIS TOOL →

Free to start. No card required.

EXPLORE

More Obsidian Memory MCP tools

Destructive delete_entities Delete multiple entities and their associated relations from the knowledge graph Destructive delete_observations Delete specific observations from entities in the knowledge graph Write add_observations Add new observations to existing entities in the knowledge graph Write create_entities Create multiple new entities in the knowledge graph Write create_relations Create multiple new relations between entities in the knowledge graph. Relations should be Write open_nodes Open specific nodes in the knowledge graph by their names Read read_graph Read the entire knowledge graph Read search_nodes Search for nodes in the knowledge graph based on a query

All 9 Obsidian Memory MCP tools →

Destructive tools on other servers

Frida Game Hacking MCP clear_scan MegaMemory remove_concept Frida Agent MCP kill_app 1MCP Server mcp_uninstall

Go deeper

Critical-risk tools in Obsidian Memory MCP → Every critical-risk tool this server exposes, in one view.
All critical-risk MCP tools → Every critical-risk tool across the catalogue, and the policy pattern that contains them.
The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

What does the delete_relations tool do? +

Delete multiple relations from the knowledge graph. It is categorised as a Destructive tool in the Obsidian Memory MCP MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.

How do I enforce a policy on delete_relations? +

Register the Obsidian Memory MCP server in PolicyLayer and add a rule for delete_relations: 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 Obsidian Memory MCP. Nothing to install.

What risk level is delete_relations? +

delete_relations is a Destructive tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.

Can I rate-limit delete_relations? +

Yes. Add a rate_limit block to the delete_relations 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.

How do I block delete_relations completely? +

Set action: deny in the PolicyLayer policy for delete_relations. 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.

What MCP server provides delete_relations? +

delete_relations is provided by the Obsidian Memory MCP server (yunaga224/obsidian-memory-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Obsidian Memory MCP tool call.

Deterministic rules across all 9 Obsidian Memory MCP tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.

GOVERN OBSIDIAN MEMORY →

Free to start. No card required.

9 Obsidian Memory MCP tools catalogued and risk-classified — across an index of 42,500+ MCP servers.

// WHAT DELETE_RELATIONS ON OBSIDIAN MEMORY MCP DOES

// THE RISK

// HOW TO CONTROL DELETE_RELATIONS

// EXPLORE