codec exec: control thinking level, ignore AGENTS.md ?

Question

### What is the type of issue?

Documentation is missing

### What is the issue?

sometimes I want to run things like

```
codex  exec "show me macos cmd to do ..." --model gpt-5-codex
```

without having it read the the AGENTS.md (does it read it?), and I also would like to control the "thinking level" (probably only available with gpt-5 like in the code-agent). What options should I use for these?

### Where did you find it?

_No response_