pylon_create_attachment_from_url · Pylon MCP: Risk & Policy

WHAT IT DOES

What pylon_create_attachment_from_url does on Pylon

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

WHY IT NEEDS A POLICY

Why pylon_create_attachment_from_url needs a policy

The tool creates and stores a new attachment resource by downloading content from an external URL. This is a reversible write operation—attachments can typically be deleted or replaced.

From the tool's definition Tool name contains 'create' and description states 'Create a Pylon attachment by downloading a file from a public URL.' This is a creation operation that adds new data (an attachment) to the system.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

pylon_create_attachment_from_url Rate-limited

pylon_create_attachment_from_url 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": {
    "pylon_create_attachment_from_url": {
      "limits": [
        {
          "counter": "pylon_create_attachment_from_url_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 Pylon, so you can run agents against it safely.

FAQ

Questions about pylon_create_attachment_from_url

What does the pylon_create_attachment_from_url tool do? +

Create a Pylon attachment by downloading a file from a public URL. It is categorised as a Write tool in the Pylon MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on pylon_create_attachment_from_url? +

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

What risk level is pylon_create_attachment_from_url? +

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

Can I rate-limit pylon_create_attachment_from_url? +

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

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

pylon_create_attachment_from_url is provided by the Pylon MCP server (@customer-support-success/pylon-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.