hfss_list_variables

THE RISK

Low Risk

Why hfss_list_variables needs a policy

This tool retrieves and queries existing design variables from the HFSS simulation environment without modifying, executing, or deleting any data. It has no side effects and represents a straightforward informational query operation.

From the tool's definition Tool name includes 'list' and description states 'List all design variables' — a pure data retrieval operation with no modification or execution.

Documented attack patterns abuse exactly the kind of access hfss_list_variables gives an agent:

POLICY

How to control hfss_list_variables

PolicyLayer is an MCP gateway — it sits between your AI agents and HFSS MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for hfss_list_variables:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "hfss_list_variables": {}
  }
}

hfss_list_variables is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.

Create a free account and register HFSS MCP Server — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

CAP THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More HFSS MCP Server tools

Destructive hfss_delete_variable Delete a design variable Execute hfss_launch_app Launch a new HFSS application with GUI (creates new session) Execute hfss_restart_app Restart HFSS application Execute hfss_run_analysis Run simulation analysis Execute hfss_start_app Connect to existing HFSS application (no new session created) Execute hfss_stop_app Stop/Close HFSS application and release resources Write hfss_assign_radiation_boundary Assign a radiation boundary to a face Write hfss_assign_wave_port Assign a wave port to a face

All 28 HFSS MCP Server tools →

Read tools on other servers

M-Team MCP Server get_torrent_detail YouTube MCP Server search_channel Android Forensics ADB MCP Server parse_browser_history 0xarchive web3_challenge

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Data exfiltration → How read access becomes an exfiltration channel when chained with untrusted content.
MCP token cost → What connecting this server costs in context-window tokens on every request.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about hfss_list_variables

What does the hfss_list_variables tool do? +

List all design variables. It is categorised as a Read tool in the HFSS MCP Server MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on hfss_list_variables? +

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

What risk level is hfss_list_variables? +

hfss_list_variables is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit hfss_list_variables? +

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

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

hfss_list_variables is provided by the HFSS MCP Server MCP server (leonardwy/hfss_mcpserver). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every HFSS MCP Server tool call.

Start from HFSS MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →