add_document · Knowledge MCP: Risk & Policy

WHAT IT DOES

What add_document does on Knowledge

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

WHY IT NEEDS A POLICY

Why add_document needs a policy

This tool creates new data (markdown documents) in the knowledge base. It is a Write operation because it adds/creates content that can be subsequently modified or removed.

From the tool's definition Tool description explicitly states 'Add a markdown document to the knowledge base', which is a reversible creation/modification operation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_document Rate-limited

add_document 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": {
    "add_document": {
      "limits": [
        {
          "counter": "add_document_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 Knowledge, so you can run agents against it safely.

FAQ

Questions about add_document

What does the add_document tool do? +

Add a markdown document to the knowledge base. It is categorised as a Write tool in the Knowledge MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on add_document? +

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

What risk level is add_document? +

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

Can I rate-limit add_document? +

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

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

add_document is provided by the Knowledge MCP server (numericalpie/knowledge-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.