zemax_set_variable · Zemax MCP: Risk & Policy

WHAT IT DOES

What zemax_set_variable does on Zemax

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

WHY IT NEEDS A POLICY

Why zemax_set_variable needs a policy

This tool creates or modifies design parameters in the optical simulation by designating cells as optimization variables. It does not delete data (not Destructive), execute arbitrary code (not Execute), move money (not Financial), or read-only query (not Read). It is a Write operation because it persistently alters the design configuration.

From the tool's definition Tool name 'zemax_set_variable' and description state it 'Make a Lens Data cell a VARIABLE for optimization.' This modifies optical design parameters within Zemax OpticStudio, specifically marking cells as variables to enable optimization workflows.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

zemax_set_variable Rate-limited

zemax_set_variable 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": {
    "zemax_set_variable": {
      "limits": [
        {
          "counter": "zemax_set_variable_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 Zemax, so you can run agents against it safely.

FAQ

Questions about zemax_set_variable

What does the zemax_set_variable tool do? +

Make a Lens Data cell a VARIABLE for optimization. cell is 'radius',. It is categorised as a Write tool in the Zemax MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on zemax_set_variable? +

Register the Zemax MCP server in PolicyLayer and add a rule for zemax_set_variable: 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 Zemax. Nothing to install.

What risk level is zemax_set_variable? +

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

Can I rate-limit zemax_set_variable? +

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

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

zemax_set_variable is provided by the Zemax MCP server (webworn/zemax-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.