Well, I made a simple Text UI tool for server administrators. It is written by use of Source scripting possibilities only. As for now, menu has quite a few functions, but a lot of them can be added.
This tool works by sending RCON commands to dedicated TF2 server and is controlled in-game with numpad. It requires rcon_address and rcon_password string in order to work. Installation guide may be found in readme. Some in-game screens of menu:

So, it's my first ever submission to such a contest, but it was quite interesting, and, i hope, worth it's effort. Thanks!

p.s. some functions require sv_cheats to be turned on