trigger_transcription · Mux MCP: Risk & Policy

WHAT IT DOES

What trigger_transcription does on Mux

AI agents invoke trigger_transcription to trigger actions in Mux. 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 trigger_transcription needs a policy

This tool triggers an external operation (transcription pipeline) whose execution has side effects (resource consumption, caption generation) but is reversible (transcription can be regenerated or deleted). It is not a simple Read operation, nor is it Destructive or Financial. Execute is appropriate because it initiates a computational process dependent on arguments (video selection).

From the tool's definition Tool name 'trigger_transcription' combined with server description stating 'generating auto-captions' indicates this initiates an external transcription/caption generation process on video assets.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

trigger_transcription Rate-limited

trigger_transcription 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": {
    "trigger_transcription": {
      "limits": [
        {
          "counter": "trigger_transcription_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 Mux, so you can run agents against it safely.

FAQ

Questions about trigger_transcription

What does the trigger_transcription tool do? +

Trigger Mux. It is categorised as a Execute tool in the Mux MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on trigger_transcription? +

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

What risk level is trigger_transcription? +

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

Can I rate-limit trigger_transcription? +

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

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

trigger_transcription is provided by the Mux MCP server (nobanks/mux-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.