vna_calibration_start · Copper Mountain Vna MCP

WHAT IT DOES

What vna_calibration_start does on Copper Mountain Vna

AI agents invoke vna_calibration_start to trigger actions in Copper Mountain Vna. 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 vna_calibration_start needs a policy

This tool triggers execution of a calibration procedure on physical test equipment (Copper Mountain VNA). Calibration is a hardware operation that modifies the instrument's state and measurement coefficients. While not destructive (reversible via recalibration) and not a direct read, it actively executes an external operation on the hardware, placing it in the Execute category.

From the tool's definition 'Start calibration procedure' with automatic port extension disabling indicates triggering a calibration routine on the VNA hardware.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

vna_calibration_start Rate-limited

vna_calibration_start 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": {
    "vna_calibration_start": {
      "limits": [
        {
          "counter": "vna_calibration_start_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 Copper Mountain Vna, so you can run agents against it safely.

FAQ

Questions about vna_calibration_start

What does the vna_calibration_start tool do? +

Start calibration procedure. Automatically disables port extension on all ports before starting (port extension during calibration causes incorrect coefficients). Returns port_extension_was_disabled: true if any ports had extension enabled. It is categorised as a Execute tool in the Copper Mountain Vna MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on vna_calibration_start? +

Register the Copper Mountain Vna MCP server in PolicyLayer and add a rule for vna_calibration_start: 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 Copper Mountain Vna. Nothing to install.

What risk level is vna_calibration_start? +

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

Can I rate-limit vna_calibration_start? +

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

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

vna_calibration_start is provided by the Copper Mountain Vna MCP server (rfingadam/copper-mountain-vna-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.