cc @soyuka This is a followed up of #7412 to have a 100% consistent behavior with the RequestBody override.

When you override the RequestBody:

• Without description, it use the default one
• With a '' description, it use ''

After #7412

• If you override the response without a description, it use ''
• If you override the response with an explicit '', it use ''

So you cannot rely on the default description provided by the OpenAiFactory.
On the opposite, just adding

if (!$response->getDescription()) {
     $response = $response->withDescription($description);
}

will remove the ability to "hide" the description by voluntary setting ''. Feature which is possible on RequestBody.

So the only way is to use a nullable description on Response (same way it's nullable on RequestBody).

• Null means use the defaut value from OpenAiFactory
• '' means use nothing