NotMeNotYou said:
The second part is correct, if you wish to edit the description to match the description on the original upload you're more than welcome to do so. The thing we forbid is writing made up crap to hope and influence the tags or other such nonsense.
If you do edit descriptions be mindful if the uploader is either the artist or the commissioner, you should let them deal with their descriptions in those cases.

Might I suggest changing it to "making shit up" or "making up non-factual information" or just something a little clearer than "creating information?" While it's currently very PC and intelligently worded not everyone will fully understand what it means, as you've already seen. If it means making sure it's clearer then I'm all for being a bit cruder or less eloquent, and definitely less ambiguous, in wording.