The description of your sources do not carry over to the models.

Conventionally, you should declare the descriptions of your models in the models/ folder in .yml files, as described here: https://docs.getdbt.com/reference/model-properties

One convention I have often seen is to have the yml files in each of the models subfolders, e.g.

models/intermediate/_int__models.yml
models/intermediate/int_some_model.sql