delete_kb_documents

THE RISK

Critical Risk

Why delete_kb_documents needs a policy

This tool permanently removes documents from a Knowledge Base without the ability to undo the action. While not as critical as deleting an entire system or financial data, document deletion is destructive in nature and represents a high-severity risk if an AI agent is misdirected to delete important knowledge base entries.

From the tool's definition Tool name contains 'delete' and description explicitly states 'Delete documents from a Knowledge Base by their IDs.' The action is irreversible removal of data.

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

POLICY

How to control delete_kb_documents

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

policy.json

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

delete_kb_documents 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 MemOS — 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

Related tools and policies

More MemOS tools

Destructive delete_memory Trigger: User explicitly asks to delete memories. Purpose: Delete memories by ID. STRI Destructive remove_knowledge_base Trigger: User requests to remove a Knowledge Base from the project. Purpose: Remove a Kn Write add_feedback Trigger: User wants to MODIFY/UPDATE memories, OR as the final step of a DELETION workflow Write add_kb_document Trigger: Use when the user provides document content, a file URL, or a local file path to Write add_message Trigger: 1. AUTO-INVOKED: After every answer to save dialogue history. 2. USER IN Write create_knowledge_base Trigger: When the user asks to create a project-specific or domain-specific Read get_kb_documents Trigger: Use to retrieve detailed information about specific documents in a Knowledge Base Read get_user_profile Trigger: MANDATORY for queries like

All 10 MemOS tools →

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Go deeper

Critical-risk tools in MemOS → 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.
Blast radius → How much damage one compromised or confused agent can do — and how to bound it.
Tool call approval → Approval gates on individual tool calls: auto-allow, prompt, or deny.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about delete_kb_documents

What does the delete_kb_documents tool do? +

Trigger: Use when specific documents in a Knowledge Base should be removed. Purpose: Delete documents from a Knowledge Base by their IDs. It is categorised as a Destructive tool in the MemOS 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_kb_documents? +

Register the MemOS MCP server in PolicyLayer and add a rule for delete_kb_documents: 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 MemOS. Nothing to install.

What risk level is delete_kb_documents? +

delete_kb_documents 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_kb_documents? +

Yes. Add a rate_limit block to the delete_kb_documents 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_kb_documents completely? +

Set action: deny in the PolicyLayer policy for delete_kb_documents. 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_kb_documents? +

delete_kb_documents is provided by the MemOS MCP server (memtensor/memos-api-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every MemOS tool call.

Start from MemOS, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →