start_stream · Restream MCP Server MCP: Risk & Policy

WHAT IT DOES

What start_stream does on Restream MCP Server

AI agents invoke start_stream to trigger actions in Restream MCP Server. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why start_stream needs a policy

Starting a stream is an executable action that triggers real-world effects across external platforms—it engages broadcasting infrastructure and makes content live to audiences. While reversible (via stop_stream), it's an active operation with external side effects dependent on parameters, making it Execute rather than Write.

From the tool's definition Tool name is 'start_stream' and description states 'Start a new stream with optional settings'. This initiates an external operation (streaming to multiple platforms like YouTube, Twitch, Facebook) whose effects depend on the provided settings arguments.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

start_stream Rate-limited

start_stream stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "start_stream": {
      "limits": [
        {
          "counter": "start_stream_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Restream MCP Server, so you can run agents against it safely.

FAQ

Questions about start_stream

What does the start_stream tool do? +

Start a new stream with optional settings. It is categorised as a Execute tool in the Restream MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on start_stream? +

Register the Restream MCP Server MCP server in PolicyLayer and add a rule for start_stream: 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 Restream MCP Server. Nothing to install.

What risk level is start_stream? +

start_stream is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit start_stream? +

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

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

start_stream is provided by the Restream MCP Server MCP server (shaktech786/restream-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.