It's a neat idea.

If it is a tool for drawing perspective lines, can anyone post a picture of the tool. When I Google it, all I see are the typical 45 and 60 degree triangles.

I was far more primitive...I had a table with a rubber layer glued on top (so you could cut on it) so I just stuck in some thumb tacks at the vanishing points and used a ruler.

>Draw 2 lines all the way across the paper that define your perspective plane.

>On the edges of the paper where the lines cross, draw tic marks that subdivide the distance between those points evenly.  As many divisions as you like.

>Connect the dots.

>Bob's your uncle.

As long as the spacing between the dots is regular, those lines are mathematically guaranteed to converge together at a point.  You can easily build a 3 point space with all three vanishing points waaaaay off the page for that "telephoto" look.  

You can also start from the other end of the process, and just draw tic marks along the edge that are evenly spaced, like (example) 3/4 inch on one side, and 7/8ths on the other side.  This can work well if the horizon is in the shot.

Experiment!  You'll find many variations of the idea.

The dot spacing can even be an arbitrary length if you have a second piece of paper (like a post-it, or back of business cards work great).  Just draw the tic marks of the desired spacing on the edge of the second piece of paper to use as a gage to draw the dots on the edges of the work.  It's even a quick way to check if you did it right, since you can just run the second piece of paper down the edge to see if the dots match up.