What Google reads
For search, Google Play reads your title (30 characters), your short description (80) and your long description (4,000). There is no hidden keyword field on Google Play, so everything you want to rank for has to appear in text a person could also read.
The title carries the most weight, then the short description, then the long description. A word that appears only once in the long description is a weak signal. A word in the title is a strong one.
What is not text
Text gets you into the results. Where you land among them is also shaped by how people treat your app: installs and how fast they grow, ratings, how many people keep the app, and how recently you updated it. This is why a small app with a perfect title often loses to a big app with a messy one.
Why the top results change
Results depend on the country and the language of the search, and they move a place or two during the day. Two people in the same country can see slightly different orders. This is why a rank is best read as a trend over days, not as a single exact number.
What to do with this
- Put your most important phrase in the title, in words a person would type.
- Use the short description for the second most important phrases, written as a sentence a person would read.
- Repeat important words in the long description naturally. Stuffing hurts conversion and can get a listing rejected.
- Check ranks in the country and language you care about, not only your own.