[ENHANCEMENT] Warn users to not use gpt5-codex and instead use a normal gpt5 model

[nickcatal]

Problem (one or two sentences)

gpt5-codex performs horribly with Roo's tool call functionality compared to the normal GPT-5 models. Roo immediately performed vastly better just by switching to the normal GPT5 model. It'd be great if you were warned if you used this model that you may experience degraded performance and the solution is to move to a normal GPT-5 model.

Context (who is affected and when)

Any user of gpt5-codex on any provider that supports it

Desired behavior (conceptual, not technical)

There should be a note somewhere if you select it that you should instead use a normal gpt5 product.

Constraints / preferences (optional)

No response

Request checklist

• I've searched existing Issues and Discussions for duplicates
• This describes a specific problem with clear context and impact

Roo Code Task Links (optional)

No response

Acceptance criteria (optional)

No response

Proposed approach (optional)

No response

Trade-offs / risks (optional)

No response

[roomote]

I'm exploring a potential fix for this issue to add a warning when users select gpt5-codex models. I'll open a PR to share progress.

[roomote]

Opened PR #8985 with a fix for this issue: #8985

The implementation adds a performance warning that displays when users select the gpt5-codex model, recommending they use standard GPT-5 models instead for better tool call performance. Feedback welcome!

[daniel-lxs]

Hey @nickcatal Thank you for the report, we are working on these models to get them to perform better so this is not planned for now.