When the Revit MCP Server Reports Only One Tool, Use Python Instead

Here’s what the conversation may look like:

Load the Revit MCP Tools

I loaded the Revit tools that are available right now, and I can see your running Revit session. Instance 11448 has 261104 VAV System Retail open, from X:\BIMtopia\BIMtopia Academy\MEP Systems\.

Only part of the Revit tools are available, though:

• Revit MCP Experimental Technical Preview: connected, but it currently provides only one tool, which lists running Revit instances. Its notes mention other tools, such as one that reads the active document, but those aren't available in this session.

• Click the Copy button to copy the Python script to your clipboard.

• Open Manage > Visual Programming > Dynamo.

• Create a new Dynamo Workspace.

• Add a Python Script node to the Dynamo Workspace.

• Right-click the Python Script node and choose Edit.

• Select all the code in the Python Script mode and delete it. (Ctrl-A, then Delete key.)

• Paste in the Python script that you copied to your clipboard.

• Click Save and Run.
• Close the Python Script node.

• Attach a Watch node to read the output messages from the script.

• This Python Script creates a CSV file with the requested info.
• Claude suggests attaching the CSV file air_terminals.csv from your Documents folder to your next message. That's easier than copying from the Watch node. I'll turn it into a clean list or table, with airflow totals by system or level if you want them.

The model has 14 air terminals, all on L1. Each one is set to 500 CFM.

Supply Air: Mechanical Supply Air 2 (5 diffusers, 2,500 CFM)

Supply Air: Mechanical Supply Air 12 (6 diffusers, 3,000 CFM)

Return Air: Mechanical Return Air 1 (3 diffusers, 1,500 CFM)

Totals: 5,500 CFM supply and 1,500 CFM return.

A few things stand out:

• Return is much lower than supply. Return is 4,000 CFM below supply. That's fine if the difference is made up by exhaust, relief, or deliberate pressurization. If not, the return side may be missing terminals or have flows that weren't updated from a default.
• Every terminal is exactly 500 CFM. This often means the flows are placeholder values rather than numbers taken from a load calculation.
• The Type and Space columns came back blank. The model doesn't appear to have MEP Spaces placed. The type name lookup in my script also failed, which happens on Dynamo 3.x. I can fix that line if you need type names, such as the diffuser sizes.

• Click the Copy button to copy the Python script to your clipboard.

• Open Manage > Visual Programming > Dynamo.

• Create a new Dynamo Workspace.

• Add a Python Script node to the Dynamo Workspace.

• Right-click the Python Script node and choose Edit.

• Select all the code in the Python Script mode and delete it. (Ctrl-A, then Delete key.)

• Paste in the Python script that you copied to your clipboard.

• Click Save and Run.
• Close the Python Script node.

• Attach a Watch node to read the output messages from the script.

• This Python Script changes the Revit elements directly in the model.