Hi Uli,
If there is a factual error (rather than style) in the description, by all means suggest an update request using the Eintrag aktualisieren link in the category it is listed in.
Some things to consider:
Describe the reason for the change request accurately, it helps for us to know what to look for.
The change must be visible on the site, or the reviewer will likely ignore it.
Avoid the temptation to keyword stuff or optimize the title or description - the reviewer may not notice where the actual change is.
Like with listings, delays are variable, so please be patient.