The specific example is geiser. In this case when I hit tab in the geiser repl it brings up a bunch of possible auto completions and once I select which one I want I get the type signature of the function in the echo area. But I can't for the life of me figure out how to get it to show the documentation for the scheme function.
If anyone has used Ipython command line, what I'm looking for would be the equivalent of >function? on the prompt there.