create_doc · Lark MCP: Risk & Policy

WHAT IT DOES

What create_doc does on Lark

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

WHY IT NEEDS A POLICY

Why create_doc needs a policy

Creating a new document is a Write action—it modifies the state of the Feishu workspace by adding new content, but the action is reversible (the document can be deleted). Severity is medium because unauthorized document creation could clutter workspaces, spam collaborative systems, or create misleading information, but the impact is contained to document creation without financial or destructive consequences.

From the tool's definition Tool name 'create_doc' and description 'Create a new Feishu document' explicitly indicates document creation. This is a reversible write operation that generates new data.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_doc Rate-limited

create_doc 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": {
    "create_doc": {
      "limits": [
        {
          "counter": "create_doc_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 Lark, so you can run agents against it safely.

FAQ

Questions about create_doc

What does the create_doc tool do? +

Create a new Feishu document with optional content in Markdown format. It is categorised as a Write tool in the Lark 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_doc? +

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

What risk level is create_doc? +

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

Can I rate-limit create_doc? +

Yes. Add a rate_limit block to the create_doc 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_doc completely? +

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

create_doc is provided by the Lark MCP server (lovelts/lark-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.