We know that the mongo does not save metadata about the collection, but have same features to help do decrease the size of database.

We usually use short names to fields, to help do decrease the size of the database (usually our application do that for us), but it does not help when you want to do a search on database in the mongoldb console. The mongo already had that feature for indexes, I just don't know the size of the description in the index. I hope there is no limit or large enougth to put all information we need about the collection

It will be nice, if we can put a description in the collections, because we can specify the what are the fields, what they represent in the application.

I think that is reasonable, but it's up to you guys, it's an idea.