zeph_file · Zeph To MCP: Risk & Policy

WHAT IT DOES

What zeph_file does on Zeph To

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

WHY IT NEEDS A POLICY

Why zeph_file needs a policy

This tool writes data (a text file) to user devices, making it a Write category action. Severity is medium because an AI agent could be tricked into sending sensitive, malicious, or unwanted files to users, but the action is reversible (files can be deleted).

From the tool's definition Tool description states 'Send a text file to the user', which is a write operation that creates or transfers data to user storage/devices. While not destructive, it modifies the user's file system state.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

zeph_file Rate-limited

zeph_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": {
    "zeph_file": {
      "limits": [
        {
          "counter": "zeph_file_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 Zeph To, so you can run agents against it safely.

FAQ

Questions about zeph_file

What does the zeph_file tool do? +

Send a text file to the user\. It is categorised as a Write tool in the Zeph To MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on zeph_file? +

Register the Zeph To MCP server in PolicyLayer and add a rule for zeph_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 Zeph To. Nothing to install.

What risk level is zeph_file? +

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

Can I rate-limit zeph_file? +

Yes. Add a rate_limit block to the zeph_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 zeph_file completely? +

Set action: deny in the PolicyLayer policy for zeph_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 zeph_file? +

zeph_file is provided by the Zeph To MCP server (zeph-to/mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.