the Ms license transfer tool is for moving the license from one xbox to the next. (say one got broke) there is a work around though so you dont have to sign in to both profiles.
If you download something with your profile, to your xbox, your xbox holds the license for that data. this means any other profile on this same xbox can also use that data. so as long as both profiles are stored on the same xbox, and the license is on that xbox, there is no need to sign in to both profiles.
now, if the gamertag with the DLc came from another xbox, and the old xbox holds the license, you need to transfer the license (using fookz tool) so both profiles and licenses are on the same xbox. (recovering just the profile wont allow both users to use the content, you must move the profile and its license.