feishu_message_send · Feishu MCP: Risk & Policy

WHAT IT DOES

What feishu_message_send does on Feishu

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

WHY IT NEEDS A POLICY

Why feishu_message_send needs a policy

This tool creates new messages (Write category) rather than merely reading or querying. While messages can be deleted later, the act of sending is a reversible write operation. Severity is high because an AI agent could send spam, phishing messages, misinformation, or impersonate users at scale across the organization.

From the tool's definition Tool name 'feishu_message_send' and description '发送飞书消息给用户或群组' (send Feishu messages to users or groups) indicates the tool creates and sends messages to Feishu users or groups.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

feishu_message_send Rate-limited

feishu_message_send 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": {
    "feishu_message_send": {
      "limits": [
        {
          "counter": "feishu_message_send_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 Feishu, so you can run agents against it safely.

FAQ

Questions about feishu_message_send

What does the feishu_message_send tool do? +

发送飞书消息给用户或群组. It is categorised as a Write tool in the Feishu MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on feishu_message_send? +

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

What risk level is feishu_message_send? +

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

Can I rate-limit feishu_message_send? +

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

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

feishu_message_send is provided by the Feishu MCP server (zlplzp123wyt/feishu-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.