If I want to import packages, do I have to manually write import() directives into my NAMESPACE file? It seems like roxyg
Expanding on my comment, if you want to automatically add namespace directives for packages/functions you import, you can do so by adding the @imports package or @importFrom package function line to the roxygen2 documentation header of your function.
However, as @hadley pointed out, it will only modify the NAMESPACE, but not affect the package DESCRIPTION