OpenAI's Prompt guidance for GPT 5.5

OpenAI has published official prompting guidance for their latest model GPT 5.5

👉 Prompt guidance | OpenAI API

Here are some of the takeaways:

GPT-5.5 works best when prompts define the outcome and leave room for the model to choose an efficient solution path.

• Describe the outcomes, not step by step on how to do like we used to write for older models. The model can figure that out on its own
• Reasoning effort defaults to medium - change it to low/high based on your latency/cost needs and use case.

Migrating Old Prompt using Codex

You can invoke $openai-docs migrate this project to gpt-5.5 which uses Docs Skill under the hood.