This feature is one of the strongpoints in evolvEd®, because it actually tells you what kind of arguments a certain function requires as well as telling what it returns.
To Activate it, just type a start-paranthesis after the function (().
Example (you are working with a perl-file and enter the split()-function), once you have typed the '(' you will get a hint-box that tells you what the split()-function does, as well as what it accepts as arguments.
By the moment, evolvEd supports this feature on all C/C++, Perl, Java, PHP, StreamServe and Delphi/Pascal functions.
(which means way over 10000 functions!)