[DiapDealer]

Removing tags in calibre doesn't remove any description tags that are part of the original ebook's internal metadata. It only removes those tags/items from calibre's own metadata database. After editing the metadata in calibre, you'd need to then do a conversion (ePub->ePub, MOBI->MOBI, etc...) to permanently remove the tags from the ebook's internal metadata. But even then, re-importing the original ebook would cause calibre to re-read the original metadata and put those tags right back. The better solution would probably be to edit the metadata of the ebooks before you ever import them into calibre in the first place.