How many words are in a good sentence? This was asked by an absolute idiot who was rude. This is also incorrect and she insisted this was correct, despite having never been a writer professionally in her life (her admission). Oh well, just remember the answer I guess.

The interviewer was probably trying to ask about readability, but could only go so far as to ask about word count. I'd bring some info about Flesch-Kincaid to the interview table.

What a stupid question. It all depends on your audience and the type of material you are writing. Stating 12 words as an absolute is laughable. There are other more important things to ask a tech writer. I should know, 25 years in the business.

As many as it takes for the client/customer to understand the application.

As many as it takes for the client/customer to understand what the application does and the steps needed to create the program appropriately.

As many as it takes for the client/customer to understand what the application does and the steps that be needed to use the program appropriately.