sprout_start_multipart_upload · Sprout MCP: Risk & Policy

WHAT IT DOES

What sprout_start_multipart_upload does on Sprout

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

WHY IT NEEDS A POLICY

Why sprout_start_multipart_upload needs a policy

This tool initiates a media upload process, which is a write operation — it creates a new upload session/submission on the server. It does not execute code, delete data, or involve financial transactions. The severity is medium because it begins a multi-step upload of large files, which could be misused to upload unwanted or malicious media content, but it is reversible and does not directly publish content.

From the tool's definition Start a multipart media upload for files over 50MB. Optionally provide a URL to download from. Returns a submission_id for subsequent upload parts and completion.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

sprout_start_multipart_upload Rate-limited

sprout_start_multipart_upload 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": {
    "sprout_start_multipart_upload": {
      "limits": [
        {
          "counter": "sprout_start_multipart_upload_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 Sprout, so you can run agents against it safely.

FAQ

Questions about sprout_start_multipart_upload

What does the sprout_start_multipart_upload tool do? +

Start a multipart media upload for files over 50MB. Optionally provide a URL to download from. Returns a submission_id for subsequent upload parts and completion. It is categorised as a Write tool in the Sprout MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on sprout_start_multipart_upload? +

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

What risk level is sprout_start_multipart_upload? +

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

Can I rate-limit sprout_start_multipart_upload? +

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

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

sprout_start_multipart_upload is provided by the Sprout MCP server (@oliverames/sprout-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.