set_default_printer

THE RISK

Medium Risk

Why set_default_printer needs a policy

This tool modifies system configuration state by changing which printer is designated as default. It is Write category because: (1) it creates or modifies data reversibly, (2) the change can be undone by setting a different default printer, and (3) it has no destructive or financial consequences.

From the tool's definition Tool name 'set_default_printer' and description 'Set a printer as the default printer' indicate configuration modification. This modifies system printer settings (default printer selection) which is a reversible write operation.

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

POLICY

How to control set_default_printer

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

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "set_default_printer": {
      "limits": [
        {
          "counter": "set_default_printer_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

set_default_printer 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.

Create a free account and register MCP Printer Server — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

LIMIT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More MCP Printer Server tools

Destructive cancel_print_job Cancel a specific print job by job ID or cancel all jobs for a printer. Execute print_file Print a file to a specified printer. Supports PDF, text, and other common formats. Can spe Read get_config Get the current MCP Printer configuration settings. Returns environment variables and thei Read get_default_printer Get the name of the default printer Read get_page_meta Get page count and physical sheet information for a file before printing. Pre-renders the Read get_print_queue Check the print queue for a specific printer or all printers. Shows pending and active pri Read list_printers List all available printers on the system with their status. Returns printer names, states

All 8 MCP Printer Server tools →

Write tools on other servers

M-Team MCP Server download_torrent YouTube MCP Server generate_video_title Android Forensics ADB MCP Server combine_reports 0xarchive web3_signup

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Argument validation → Checking tool call arguments against schema and policy before they run.
Scoped token → Per-person credentials that grant a defined subset of servers and tools.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about set_default_printer

What does the set_default_printer tool do? +

Set a printer as the default printer. It is categorised as a Write tool in the MCP Printer 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 set_default_printer? +

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

What risk level is set_default_printer? +

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

Can I rate-limit set_default_printer? +

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

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

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

Enforce policy on every MCP Printer Server tool call.

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

CHECK YOUR STACK →