GPT-5 used to do this on release, but seems to have reverted back, especially on the codex versions. This may well be a feature.
I joked that this is the side effect of asking it to act like a senior software engineer. It tends to talk back and do its own thing. There was that one time when the thought processes went "I'm a full stack engineer" > "I'm expanding my connections on LinkedIn" > "I'm establishing myself as a tech writer" > "I'm evaluating classes in professional writing". It does have introspection capabilities, but one could argue it's just a bug or emergent.
Anyway, option 1: why not just use Sonnet? Heck you can use Haiku if you're giving it clear instructions. The thinking ones do perform worse on clear tasks. You also get your rolled back version.
Option 2: Use role prompting [0]
Give it some junior engineer role where it's expected to follow instructions exactly as given.
GPT-5 used to do this on release, but seems to have reverted back, especially on the codex versions. This may well be a feature.
I joked that this is the side effect of asking it to act like a senior software engineer. It tends to talk back and do its own thing. There was that one time when the thought processes went "I'm a full stack engineer" > "I'm expanding my connections on LinkedIn" > "I'm establishing myself as a tech writer" > "I'm evaluating classes in professional writing". It does have introspection capabilities, but one could argue it's just a bug or emergent.
Anyway, option 1: why not just use Sonnet? Heck you can use Haiku if you're giving it clear instructions. The thinking ones do perform worse on clear tasks. You also get your rolled back version.
Option 2: Use role prompting [0] Give it some junior engineer role where it's expected to follow instructions exactly as given.
[0] https://platform.claude.com/docs/en/build-with-claude/prompt...