Chat Completions API missing GPT 5 changes

[the-spice-must-flow]

At least the three following (and likely a few more) options for the ChatCompletionsRequest are missing after GPT-5 release.

1. Minimal variant missing for ReasoningEffort
2. verbosity option missing
3. allowed-tools filtered list is missing.

Are these features too unstable to be included? Do they need to be made available only behind a certain feature flag?

Looking forward to updates and other libraries/tools being able to pull these in easier.