dual_upload_file · DUAL MCP Server MCP: Risk & Policy

WHAT IT DOES

What dual_upload_file does on DUAL MCP Server

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

WHY IT NEEDS A POLICY

Why dual_upload_file needs a policy

This tool creates or persists data in DUAL storage by uploading files. It is not destructive (the upload is reversible), not financial, and not execute-like in the sense of running arbitrary code—it is a targeted file storage operation.

From the tool's definition The tool description explicitly states 'Upload a file to DUAL storage' and 'Returns a public URL', indicating it creates a new stored artifact.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

dual_upload_file Rate-limited

dual_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": {
    "dual_upload_file": {
      "limits": [
        {
          "counter": "dual_upload_file_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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Instant setup, no code required.

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

FAQ

Questions about dual_upload_file

What does the dual_upload_file tool do? +

Upload a file to DUAL storage. Returns a public URL. Useful for template assets, face images, and attachments. It is categorised as a Write tool in the DUAL MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on dual_upload_file? +

Register the DUAL MCP Server MCP server in PolicyLayer and add a rule for dual_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 DUAL MCP Server. Nothing to install.

What risk level is dual_upload_file? +

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

Can I rate-limit dual_upload_file? +

Yes. Add a rate_limit block to the dual_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 dual_upload_file completely? +

Set action: deny in the PolicyLayer policy for dual_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 dual_upload_file? +

dual_upload_file is provided by the DUAL MCP Server MCP server (ro-ro-b/dual-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.