The official tutorial explains very clearly how to get an app's specific page to appear in google autocomplete. When I follow the description I can go from the autocomplete suggestion back to the page in the app. The autocomplete suggestion has the app icon along with the name that was set in .setName(mTitle). It is not clear to me, though, what role .setDescription(mDescription) plays. Where is this description visible? Is it shown in the search results if the app is listed as a result?
Google indexes both the title and the description to populate autocompletion results. So, even if you search for some content which is not there in the title but there in description, that page will show up in the auto completion results. The description is not directly shown (to answer your second question), but the page is shown as usual. Take a look at this page for more info.
来源：https://stackoverflow.com/questions/35053454/android-app-indexing-api-description-field