I think it would help to have a direct link from that section to http://german.stackexchange.com/help/on-topichttps://german.stackexchange.com/help/on-topic
We already have a prominent link to the help center at the bottom of the tour page. I think, however, that users who took the tour might have the impression they know all they need for the moment and don't need help. But IMHO they should read the on-topic article before writing a question.
There are links beneath the other sections, like "see all privileges" or "see all badges". They do not occupy too much space, and here we could write e.g. "see in detail what is on-topic for this site".
See http://german.stackexchange.com/questions/24108/how-to-say-i-like-you-with-gefallenhttps://german.stackexchange.com/questions/24108/how-to-say-i-like-you-with-gefallen as a current example where some user took the tour without getting sufficient guidance about what is on topic here and what not.