The "type" dropdown may not be clear enough for new users that don't understand that type can imply either a default ordering direction or an actual index type.

If a field "cats" is going to contain text, why wouldn't you create a "text" index? See https://www.mongodb.com/community/forums/t/just-to-point-out-do-not-name-a-field-language-if-you-are-planning-to-create-an-index/263793/7 as an example.

Perhaps the dropdown could be refined or the modal updated to make it clearer what "type" implies.