string OLD_DESC = "";
changed_description()
{
    string sD = llGetObjectDesc();
    if (sD != OLD_DESC)
    {
        OLD_DESC = sD;
        llSay(PUBLIC_CHANNEL, "Description wurde verändert!");
    }
}
float fTimer = 0.2;
default
{
    state_entry()
    {
        llSetTimerEvent(fTimer);
    }

    timer()
    {
        changed_description();
    }
}