wechat_send_message · Wechat MCP: Risk & Policy

WHAT IT DOES

What wechat_send_message does on Wechat

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

WHY IT NEEDS A POLICY

Why wechat_send_message needs a policy

This tool creates new data (messages) in an external system (WeChat). It is reversible in principle (messages can be deleted) but represents a Write operation that modifies user communication state. Severity is high because an AI agent could send unauthorized messages to contacts, impersonate the user, spam contacts, or facilitate social engineering attacks.

From the tool's definition Tool description states '向单个微信好友发送单条消息' (send a single message to a single WeChat friend). This is a message creation/sending action that modifies state by creating new messages in WeChat.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

wechat_send_message Rate-limited

wechat_send_message 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": {
    "wechat_send_message": {
      "limits": [
        {
          "counter": "wechat_send_message_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 Wechat, so you can run agents against it safely.

FAQ

Questions about wechat_send_message

What does the wechat_send_message tool do? +

向单个微信好友发送单条消息. It is categorised as a Write tool in the Wechat MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on wechat_send_message? +

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

What risk level is wechat_send_message? +

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

Can I rate-limit wechat_send_message? +

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

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

wechat_send_message is provided by the Wechat MCP server (panxingfeng/mcp_server_wechat). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.