create_hx_script · Avizo MCP Server MCP: Risk & Policy

WHAT IT DOES

What create_hx_script does on Avizo MCP Server

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

WHY IT NEEDS A POLICY

Why create_hx_script needs a policy

This tool creates new files programmatically, making it a Write operation. While file creation is reversible (files can be deleted), the severity is medium rather than low because malicious `.hx` scripts could potentially trigger unintended Avizo workflows or data processing when executed by other tools (like `launch_avizo` or `run_avizo_python`).

From the tool's definition Tool description explicitly states 'Create a timestamped Avizo `.hx` script' - the word 'Create' indicates data creation. The tool writes a new file (`.hx` script) to the MCP work directory, which is a reversible modification operation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_hx_script Rate-limited

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

FAQ

Questions about create_hx_script

What does the create_hx_script tool do? +

Create a timestamped Avizo .hx script under the MCP work directory. It is categorised as a Write tool in the Avizo MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on create_hx_script? +

Register the Avizo MCP Server MCP server in PolicyLayer and add a rule for create_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 create_hx_script? +

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

Can I rate-limit create_hx_script? +

Yes. Add a rate_limit block to the create_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 create_hx_script completely? +

Set action: deny in the PolicyLayer policy for create_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 create_hx_script? +

create_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.