slack_upload_file · Integrations MCP: Risk & Policy

WHAT IT DOES

What slack_upload_file does on Integrations MCP

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

WHY IT NEEDS A POLICY

Why slack_upload_file needs a policy

File uploads are Write operations—they create or add data reversibly. An AI agent could upload sensitive files, malware, or spam to a Slack workspace, affecting all members and cluttering shared spaces. The action is reversible (files can be deleted), so it is not Destructive.

From the tool's definition Tool name is 'slack_upload_file', which uploads a file to Slack. This creates new data (file content) in a workspace.

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 Integrations MCP, 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 Integrations MCP 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 Integrations 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 Integrations MCP. 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 Integrations MCP server (shriram-vasudevan/integrations-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.