vercel-blob-put · Mcp Gmail MCP: Risk & Policy

WHAT IT DOES

What vercel-blob-put does on Mcp Gmail

AI agents use vercel-blob-put to create or update resources in Mcp Gmail — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Mcp Gmail environment.

WHY IT NEEDS A POLICY

Why vercel-blob-put needs a policy

This tool creates or modifies data in Vercel Blob storage, which is a reversible operation (uploaded files can be deleted or overwritten). It does not execute arbitrary code, delete data irreversibly, or move money.

From the tool's definition Tool description states: 'Upload a file or data to Vercel Blob storage'. The verb 'upload' and the action of storing data indicates creation/modification of data in external storage.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

vercel-blob-put Rate-limited

vercel-blob-put 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": {
    "vercel-blob-put": {
      "limits": [
        {
          "counter": "vercel-blob-put_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 Mcp Gmail, so you can run agents against it safely.

FAQ

Questions about vercel-blob-put

What does the vercel-blob-put tool do? +

Upload a file or data to Vercel Blob storage. Returns the blob URL and metadata. It is categorised as a Write tool in the Mcp Gmail MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on vercel-blob-put? +

Register the Mcp Gmail MCP server in PolicyLayer and add a rule for vercel-blob-put: 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 Mcp Gmail. Nothing to install.

What risk level is vercel-blob-put? +

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

Can I rate-limit vercel-blob-put? +

Yes. Add a rate_limit block to the vercel-blob-put 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 vercel-blob-put completely? +

Set action: deny in the PolicyLayer policy for vercel-blob-put. 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 vercel-blob-put? +

vercel-blob-put is provided by the Mcp Gmail MCP server (@monsoft/mcp-gmail). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.