To create a message box with an attribute name and dollar-sign arguments, you can drag attribute names out of the inspector. Here's how.
Creating a message box from the inspector by dragging
Position the inspector window so that you can see part of the patcher where you want to create a message box.
Click on an attribute name and drag it into the patcher window.
If you want to connect the message box to an object, release the mouse button when the attribute is on top of an object box.
If you just want to put the message box in the patcher so you can connect it yourself later, release the mouse button where you want the message to be created.
If you want the current values of the attribute to be copied into the message box instead of dollar-sign arguments, hold down the option key when releasing the mouse button.