Lack of immediate validation and unclear error messages in Model Selection UI

[Rudresh-sisode]

Description

In the VAP UI, there are two primary issues concerning user experience with the model input section during the 'Create Assistant' process:

1. Immediate Validation Missing

Currently, the model selection input lacks immediate validation before attempting to publish an assistant. Users are allowed to hit the "Publish" button without being prompted about an incorrect or missing model selection. This can lead to unnecessary publishing attempts and a potentially frustrating user experience as errors only become apparent after a failed attempt.

2. Unclear Error Messaging

In the event of a validation issue, the error message displayed is not sufficiently informative or user-friendly. The current error message flagged in the UI is vague and does not guide the user on how to rectify the issue. This could confuse users, especially those less familiar with the platform intricacies.

[Rudresh-sisode]