list_families

Get a flat list of available family types in the current Revit model

SERVERRevit MCP Server SOURCEdemolinator/revit-mcp-server

Low RISK CLASS

Category Read

Parameters 00 required

Recommended Allowedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/demolinator-revit-mcp-server/list-families.md

WHAT IT DOES

What list_families does on Revit MCP Server

AI agents call list_families to retrieve information from Revit MCP Server without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

RISK

Why list_families is rated Low

This tool performs a read-only operation that queries and returns available family types from the Revit model. It has no side effects, does not modify any data, and poses minimal risk if invoked by an AI agent. The blast radius is limited to information disclosure only.

From the tool's definition Tool name 'list_families' and description 'Get a flat list of available family types in the current Revit model' indicate a query operation that retrieves information without modifying data.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs list_families safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Revit MCP Server, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For list_families, this is the rule to start with:

list_families Allowed

list_families is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

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

ALLOW ONLY THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Revit MCP Server, apply this rule, and every list_families call is checked against it from then on.

FAQ

Questions about list_families

What does the list_families tool do? +

Get a flat list of available family types in the current Revit model. It is categorised as a Read tool in the Revit MCP Server MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on list_families? +

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

What risk level is list_families? +

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

Can I rate-limit list_families? +

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

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

list_families is provided by the Revit MCP Server MCP server (demolinator/revit-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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