transcribe_upload_append · Video Toolkit MCP: Risk & Policy

WHAT IT DOES

What transcribe_upload_append does on Video Toolkit

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

WHY IT NEEDS A POLICY

Why transcribe_upload_append needs a policy

The tool appends data to a transcription upload session, which creates or modifies data reversibly. It is part of a multi-step upload workflow (transcribe_upload_start, transcribe_upload_append, transcribe_upload_finalize) and does not delete, execute arbitrary code, move money, or trigger external operations with unpredictable effects.

From the tool's definition Append one base64 chunk to an upload session — this modifies state by adding data to an in-progress upload.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

transcribe_upload_append Rate-limited

transcribe_upload_append 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": {
    "transcribe_upload_append": {
      "limits": [
        {
          "counter": "transcribe_upload_append_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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

FAQ

Questions about transcribe_upload_append

What does the transcribe_upload_append tool do? +

Append one base64 chunk to an upload session. It is categorised as a Write tool in the Video Toolkit MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on transcribe_upload_append? +

Register the Video Toolkit MCP server in PolicyLayer and add a rule for transcribe_upload_append: 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 Video Toolkit. Nothing to install.

What risk level is transcribe_upload_append? +

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

Can I rate-limit transcribe_upload_append? +

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

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

transcribe_upload_append is provided by the Video Toolkit MCP server (jamesanz/transcript-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.