create_knowledge_base

THE RISK

Medium Risk

Why create_knowledge_base needs a policy

This tool creates a new knowledge base, which is a reversible Write operation. It establishes a new data store but does not execute code, delete data irreversibly, or move money.

From the tool's definition Tool name is 'create_knowledge_base' and description indicates it creates a project-specific or domain-specific knowledge base. The verb 'create' is characteristic of Write operations that establish new data structures.

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

POLICY

How to control create_knowledge_base

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 create_knowledge_base:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "create_knowledge_base": {
      "limits": [
        {
          "counter": "create_knowledge_base_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

create_knowledge_base stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

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.

LIMIT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More MemOS tools

Destructive delete_kb_documents Trigger: Use when specific documents in a Knowledge Base should be removed. Purpose: Del 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 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 →

Write tools on other servers

M-Team MCP Server download_torrent YouTube MCP Server generate_video_title Android Forensics ADB MCP Server combine_reports 0xarchive web3_signup

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Argument validation → Checking tool call arguments against schema and policy before they run.
Scoped token → Per-person credentials that grant a defined subset of servers and tools.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about create_knowledge_base

What does the create_knowledge_base tool do? +

Trigger: When the user asks to create a project-specific or domain-specific. It is categorised as a Write tool in the MemOS MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on create_knowledge_base? +

Register the MemOS MCP server in PolicyLayer and add a rule for create_knowledge_base: 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 create_knowledge_base? +

create_knowledge_base is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit create_knowledge_base? +

Yes. Add a rate_limit block to the create_knowledge_base 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 create_knowledge_base completely? +

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

create_knowledge_base 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 →