Here's what you want to spec in your prompt to Claude Opus High, in order:

1. Objective. 1 sentence. this keeps the whole thing aligned.
2. Context. List containing every relevant link / file / docs / repos and what it contains. This limits search scope.
3. Constraints. List or small paragraphs describing the specific actions you need done. This limits "creative non-answers" because it literally tells it what to do
4. Output format. Just tell it if you want a table, prose, bullet points and if you want markdown in a file or just a reply. I generally ask for markdown "report". If I'm looking for something specific, I spec a table.
5. Acceptance criteria. Reitererate output format, constraints, objective in a condensed form. I often add "leave no stone unturned", but this is expensive as it easily takes 30-40 minutes on big jobs and will eat all your credits
6. Subtask decomposition. If it's a big job, specify how to break it down (i.e. what does the main task do, what do subtasks do, how to consolidate results back into main task) Leave this out for simple jobs.