I don’t know the Python module for OpenAI 
, but from what I’ve seen your prompts could change a bit.
Like I said previously, it’s bad at counting. If you ask it for “300 words”, it will probably do more or even less. Things like those “could” interfere with the prompt. Try removing overly specific words or stuff and focus on words that are well known in articles, books, etc. It will likely give you a better answer.
Remember: GPT3 is just a fancy autocomplete. It does what it has seen the most. That’s why words like “Paragraph”, “Summarize” and others produce very specific styles of text. In training it has likely seen that 95% of the time that an article that begun with the word “summary”, it followed with a specific style of text. It has “learned” that. Also, for this exact reason don’t use specific numbers (unless they’re extremely common).
Base your prompts on that knowledge and you’ll get pretty good at it 