untrust_printer
Remove a printer hostname/IP from the trusted whitelist.
This record as markdown: /tools/kiln/untrust-printer.md
What untrust_printer does on Kiln
AI agents call untrust_printer to permanently remove resources in Kiln, typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.
Why untrust_printer is rated Critical
This tool irreversibly removes an entry from a security whitelist, which could prevent legitimate access to printers and cannot be easily undone without knowing the original configuration. The action is a deletion/removal from a security-relevant data structure, making it Destructive in nature. Misuse could disrupt 3D printing operations by blocking trusted printers.
From the tool's definition Remove a printer hostname/IP from the trusted whitelist
Attacks that exploit this kind of access
The rule that runs untrust_printer safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Kiln, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For untrust_printer, this is the rule to start with:
untrust_printer is removed from the agent's tool list entirely, so the agent never calls it. The rest of the server keeps working.
The button opens the PolicyLayer dashboard: create your workspace, connect Kiln, apply this rule, and every untrust_printer call is checked against it from then on.
Questions about untrust_printer
Remove a printer hostname/IP from the trusted whitelist. It is categorised as a Destructive tool in the Kiln MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.
Register the Kiln MCP server in PolicyLayer and add a rule for untrust_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 Kiln. Nothing to install.
untrust_printer is a Destructive tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.
Yes. Add a rate_limit block to the untrust_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.
Set action: deny in the PolicyLayer policy for untrust_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.
untrust_printer is provided by the Kiln MCP server (codeofaxel/Kiln). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
More on Kiln, and thousands of servers like it.
Across the catalogue