fetch_pdf · Philosophy MCP: Risk & Policy

WHAT IT DOES

What fetch_pdf does on Philosophy

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

WHY IT NEEDS A POLICY

Why fetch_pdf needs a policy

The tool downloads a remote PDF and saves/writes it to the server's local storage. This is a Write operation (creates new data on the server). It is reversible in principle (the file could be deleted), so it does not qualify as Destructive. The blast radius is medium — an agent could fill disk space or save unexpected content, but the scope is limited to philosophy PDFs from a known open-access source.

From the tool's definition Download the open-access PDF of a PhilArchive record and save it into the server

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

fetch_pdf Rate-limited

fetch_pdf 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": {
    "fetch_pdf": {
      "limits": [
        {
          "counter": "fetch_pdf_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 Philosophy, so you can run agents against it safely.

FAQ

Questions about fetch_pdf

What does the fetch_pdf tool do? +

Download the open-access PDF of a PhilArchive record and save it into the server. It is categorised as a Write tool in the Philosophy MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on fetch_pdf? +

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

What risk level is fetch_pdf? +

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

Can I rate-limit fetch_pdf? +

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

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

fetch_pdf is provided by the Philosophy MCP server (sea9401/philosophy-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.