flexsim_step · FlexSim MCP Server MCP: Risk & Policy

WHAT IT DOES

What flexsim_step does on FlexSim MCP Server

AI agents invoke flexsim_step 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_step needs a policy

This tool executes simulation progression logic, advancing the state of a digital twin model. While not destructive (changes are not permanent; simulation can be reset), it is Execute-category because it triggers external operations (simulation engine event processing) with effects that vary based on model configuration and state.

From the tool's definition Tool enables 'Step through simulation events,' which executes discrete simulation steps with real-time effects on the running model state.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

flexsim_step Rate-limited

flexsim_step 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_step": {
      "limits": [
        {
          "counter": "flexsim_step_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_step

What does the flexsim_step tool do? +

Step through simulation events. 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_step? +

Register the FlexSim MCP Server MCP server in PolicyLayer and add a rule for flexsim_step: 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_step? +

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

Can I rate-limit flexsim_step? +

Yes. Add a rate_limit block to the flexsim_step 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_step completely? +

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

flexsim_step is provided by the FlexSim MCP Server MCP server (sethgame/mcp_flexsim). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.