calibrate_direct · Kiln MCP: Risk & Policy

WHAT IT DOES

What calibrate_direct does on Kiln

AI agents invoke calibrate_direct to trigger actions in Kiln. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why calibrate_direct needs a policy

On a 3D printer control server, 'calibrate_direct' most likely triggers a physical calibration routine (e.g., bed leveling, extruder calibration) on the printer, which constitutes executing an external operation. The 'direct' qualifier suggests it may bypass normal safety checks or confirmations, raising severity. However, the empty description significantly lowers confidence.

From the tool's definition Tool name 'calibrate_direct' on a server controlling 3D printers; description is empty and uninformative.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

calibrate_direct Rate-limited

calibrate_direct stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "calibrate_direct": {
      "limits": [
        {
          "counter": "calibrate_direct_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Kiln, so you can run agents against it safely.

FAQ

Questions about calibrate_direct

What does the calibrate_direct tool do? +

calibrate_direct. It is categorised as a Execute tool in the Kiln MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on calibrate_direct? +

Register the Kiln MCP server in PolicyLayer and add a rule for calibrate_direct: 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.

What risk level is calibrate_direct? +

calibrate_direct is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit calibrate_direct? +

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

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

calibrate_direct 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.