Medium Risk

upload_directory

upload_directory

How to control upload_directory ↓

What upload_directory does on PythonAnywhere MCP Server

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

Medium Risk

Why upload_directory needs a policy

upload_directory creates or modifies files in a remote hosting environment (PythonAnywhere). While reversible (Write rather than Destructive), the severity is high because bulk directory uploads could overwrite application code, configurations, or user data, with significant blast radius in a production context.

From the tool's definition Tool named 'upload_directory' on a server that 'manages files' on PythonAnywhere; uploads create/modify files reversibly.

Documented attack patterns abuse exactly the kind of access upload_directory gives an agent:

How to control upload_directory

PolicyLayer is an MCP gateway — it sits between your AI agents and PythonAnywhere MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for upload_directory:

policy.json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "upload_directory": {
      "limits": [
        {
          "counter": "upload_directory_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

upload_directory 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.

  1. Create a free account and register PythonAnywhere MCP Server — nothing to install.
  2. Add this policy — paste it, or build it visually.
  3. Point your MCP client (Claude, Cursor, anything) at your gateway URL.
LIMIT THIS TOOL →

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Related tools and policies

Go deeper

Questions about upload_directory

What does the upload_directory tool do? +

upload_directory. It is categorised as a Write tool in the PythonAnywhere 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 upload_directory? +

Register the PythonAnywhere MCP Server MCP server in PolicyLayer and add a rule for upload_directory: 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 PythonAnywhere MCP Server. Nothing to install.

What risk level is upload_directory? +

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

Can I rate-limit upload_directory? +

Yes. Add a rate_limit block to the upload_directory 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_directory completely? +

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

upload_directory is provided by the PythonAnywhere MCP Server MCP server (pythonanywhere/pythonanywhere-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every PythonAnywhere MCP Server tool call.

Start from PythonAnywhere MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

Free to start. No card required.

20 PythonAnywhere MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.

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