zulip_send_stream_message · Zulip MCP Server MCP

WHAT IT DOES

What zulip_send_stream_message does on Zulip MCP Server

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

WHY IT NEEDS A POLICY

Why zulip_send_stream_message needs a policy

This tool creates/writes new data (messages) to a Zulip stream, which is a reversible action—messages can be edited or deleted later. It does not execute code, delete data irreversibly, or move money.

From the tool's definition Tool name 'zulip_send_stream_message' and description 'Send a message to a Zulip stream/channel topic' indicate the tool creates new message content in a communication channel.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

zulip_send_stream_message Rate-limited

zulip_send_stream_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": {
    "zulip_send_stream_message": {
      "limits": [
        {
          "counter": "zulip_send_stream_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 Zulip MCP Server, so you can run agents against it safely.

FAQ

Questions about zulip_send_stream_message

What does the zulip_send_stream_message tool do? +

Send a message to a Zulip stream/channel topic. It is categorised as a Write tool in the Zulip 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 zulip_send_stream_message? +

Register the Zulip MCP Server MCP server in PolicyLayer and add a rule for zulip_send_stream_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 Zulip MCP Server. Nothing to install.

What risk level is zulip_send_stream_message? +

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

Can I rate-limit zulip_send_stream_message? +

Yes. Add a rate_limit block to the zulip_send_stream_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 zulip_send_stream_message completely? +

Set action: deny in the PolicyLayer policy for zulip_send_stream_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 zulip_send_stream_message? +

zulip_send_stream_message is provided by the Zulip MCP Server MCP server (prixite/zulip-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.