I recommend trying a more capable model that will read much more context too when creating specs. You can load a lot of full files into GPT 5 Pro and have it produce a great spec and give more surgical direction to CC or Codex (which don’t read full files and often skip over important info in their haste). If you have it provide the relevant context for the agent, the agent doesn’t waste tokens gathering it itself and will proceed to its work.
Is there an easy way to get a whole codebase into GPT 5 Pro? It's nice with claude to be able to say "examine the current project in the working directory" although maybe that's actually doing less than I think it is.
I wrote a tool for that: https://github.com/simonw/files-to-prompt - and there are other similar tools like repomix.
These days I often use https://gitingest.com - it can grab any full repo on GitHub has something you can copy and paste, e.g. https://gitingest.com/simonw/llm
I wrote a similiar tool myself, mostly because your tool or repomix doesn't support "presets" (saved settings):
What do you do when you repeatedly need to bundle the same thing? Bash history?omg you rock!
Of course you did - thanks, huge fan!