update_knowledge · MemoDB MCP Server MCP: Risk & Policy

WHAT IT DOES

What update_knowledge does on MemoDB MCP Server

AI agents use update_knowledge to create or update resources in MemoDB MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your MemoDB MCP Server environment.

WHY IT NEEDS A POLICY

Why update_knowledge needs a policy

This tool modifies existing knowledge records within a personal knowledge base, which is a reversible Write operation. It does not delete data (which would be Destructive) nor execute arbitrary code (Execute). The blast radius is moderate—incorrect updates could corrupt user knowledge bases or mislead an AI agent's context, but changes are reversible through subsequent corrections.

From the tool's definition Tool name 'update_knowledge' combined with description 'Update existing knowledge' indicates modification of stored knowledge base entries.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_knowledge Rate-limited

update_knowledge 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.

View as policy code

policy.json

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

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches MemoDB MCP Server, so you can run agents against it safely.

FAQ

Questions about update_knowledge

What does the update_knowledge tool do? +

Update existing knowledge. It is categorised as a Write tool in the MemoDB MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on update_knowledge? +

Register the MemoDB MCP Server MCP server in PolicyLayer and add a rule for update_knowledge: 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 MemoDB MCP Server. Nothing to install.

What risk level is update_knowledge? +

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

Can I rate-limit update_knowledge? +

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

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

update_knowledge is provided by the MemoDB MCP Server MCP server (wuyunmei/momedb-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.