Anyone who is not interested in the command-line, or anyone looking for a detailed reference to all available GNU/Linux tools should look elsewhere. This is only a summary, while it does list many commands, it's not a complete listing (I don't think it's possible to make a complete listing anyway).
This document would not be of interest to those who already have an expert knowledge of the command-line interface and do require any reference information. Or those readers who require detailed lists of options for each command, the man pages are better suited to this purpose.