The field description button should appear after the field label and before the options for a checkbox or radio button field. Otherwise, it can be confusing when the description doesn't seem to apply to the option on the first line where it now appears.
If you are referring to the blue tooltip, it is currently placed on the right for uniformity. If enough people actually wanted the tooltips next to the label itself, we could add an option or something. There's already a massive amount of config parameters so we don't want to add more than are really needed. If this is something many want, we'd add it.