upload_csv · Dune MCP: Risk & Policy

WHAT IT DOES

What upload_csv does on Dune

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

WHY IT NEEDS A POLICY

Why upload_csv needs a policy

Uploading CSV data creates new data or appends to existing datasets in Dune Analytics. This is a Write operation (reversible modification) rather than Destructive, as uploads do not irreversibly delete data. Severity is high because an AI agent uploading malicious, corrupted, or sensitive data could compromise analytics integrity and affect downstream users relying on the platform.

From the tool's definition Tool name 'upload_csv' and context within Dune Analytics platform indicating data upload capability. Sibling tools include 'create_table' and 'delete_table', confirming this server manages data persistence. Upload operations create or modify datasets.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

upload_csv Rate-limited

upload_csv 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": {
    "upload_csv": {
      "limits": [
        {
          "counter": "upload_csv_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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

FAQ

Questions about upload_csv

What does the upload_csv tool do? +

upload_csv. It is categorised as a Write tool in the Dune MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on upload_csv? +

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

What risk level is upload_csv? +

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

Can I rate-limit upload_csv? +

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

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

upload_csv is provided by the Dune MCP server (mwamedacen/dune-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.