flexsim_evaluate · FlexSim MCP Server MCP: Risk & Policy

WHAT IT DOES

What flexsim_evaluate does on FlexSim MCP Server

AI agents invoke flexsim_evaluate to trigger actions in FlexSim MCP Server. 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 flexsim_evaluate needs a policy

This tool explicitly executes arbitrary FlexScript code expressions within the FlexSim simulation engine. The ability to run arbitrary code means an AI agent could trigger unintended simulation behaviors, modify model state, or invoke destructive operations depending on what expressions are evaluated.

From the tool's definition 执行任意 FlexScript 表达式（核心方法） — 'execute arbitrary FlexScript expressions (core method)'

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

flexsim_evaluate Rate-limited

flexsim_evaluate 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": {
    "flexsim_evaluate": {
      "limits": [
        {
          "counter": "flexsim_evaluate_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 FlexSim MCP Server, so you can run agents against it safely.

FAQ

Questions about flexsim_evaluate

What does the flexsim_evaluate tool do? +

执行任意 FlexScript 表达式（核心方法）. It is categorised as a Execute tool in the FlexSim MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on flexsim_evaluate? +

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

What risk level is flexsim_evaluate? +

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

Can I rate-limit flexsim_evaluate? +

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

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

flexsim_evaluate is provided by the FlexSim MCP Server MCP server (quqbaku/flexsim-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.