A new script cmd_help.py is now available. It displays contextual help on command line like:

• commands:
  • list of commands if you type a non-complete command name, for example: /serv
  • help about command arguments if you type command (and optionally arguments), for example with /server add you'll see arguments for adding an IRC server
• options:
  • list of options if you type a non-complete option name with command /set, for example: /set weechat
  • help about option if you type a complete or unique option name with command /set, for example: /set weechat.look.command_chars

Note: this script requires version 0.3.5 of WeeChat.

Screenshot (click for full size):