Get it, it's like Code completion. I know, not quite the same thing, but catchy.
From this thread came an idea of warnings if a node would never, could never execute due to lacking input connections.
I think this could be more broadly thought of as 'node completion'
For example, at this very moment I'm using Make Text Field, and it wasn't working. I had forgot to connect the Window. The Window is all the way at the end of composition. And for almost all Vuo compositions, and certainly for all compositions initially, there is only one window.
So, Vuo could suggested connecting this automatically, (and nicely hiding the cable), if possible. If multiple options are available, it could offer those. If not possible, it could show warning.
Here's a first pass at the UI.