slack_upload_file · Mcp Gmail MCP: Risk & Policy

WHAT IT DOES

What slack_upload_file does on Mcp Gmail

AI agents use slack_upload_file 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 slack_upload_file needs a policy

File uploads are Write operations—they create or persist data in a remote system. Without a description, confidence is reduced. Medium severity accounts for potential misuse (uploading sensitive files, malware, spam) but lacks Financial or Destructive intent. The tool name-server mismatch (Slack on Gmail server) raises questions about its actual implementation, further reducing confidence.

From the tool's definition Tool named 'slack_upload_file' suggests file upload functionality to Slack. Empty description limits confidence.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

slack_upload_file Rate-limited

slack_upload_file 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": {
    "slack_upload_file": {
      "limits": [
        {
          "counter": "slack_upload_file_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 slack_upload_file

What does the slack_upload_file tool do? +

slack_upload_file. 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 slack_upload_file? +

Register the Mcp Gmail MCP server in PolicyLayer and add a rule for slack_upload_file: 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 slack_upload_file? +

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

Can I rate-limit slack_upload_file? +

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

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

slack_upload_file 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.