run_hx_script · Avizo MCP Server MCP: Risk & Policy

WHAT IT DOES

What run_hx_script does on Avizo MCP Server

AI agents invoke run_hx_script to trigger actions in Avizo 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 run_hx_script needs a policy

run_hx_script executes code (Avizo HyperScript) whose effects are determined by the script content passed as an argument. This is a classic Execute pattern: the tool triggers external operations (Avizo workflows, image processing, data transformations) with side effects that depend entirely on what the supplied `.hx` script does.

From the tool's definition Tool description states it 'Launch[es] Avizo or AvizoToGo with a `.hx` script path', indicating execution of arbitrary scripts in a specialized application environment.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

run_hx_script Rate-limited

run_hx_script 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": {
    "run_hx_script": {
      "limits": [
        {
          "counter": "run_hx_script_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 Avizo MCP Server, so you can run agents against it safely.

FAQ

Questions about run_hx_script

What does the run_hx_script tool do? +

Launch Avizo or AvizoToGo with a .hx script path. It is categorised as a Execute tool in the Avizo 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 run_hx_script? +

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

What risk level is run_hx_script? +

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

Can I rate-limit run_hx_script? +

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

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

run_hx_script is provided by the Avizo MCP Server MCP server (songyb1998/avizo-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.