Brackets should be avoided. Brackets are used to add afterthoughts, and as such appear as afterthoughts if written. Afterthoughts in theory should not appear in a word processor - the sentence can nearly always be restructured to incorporate the information. Often information that you consider useful enough to place in brackets is useful enough to appear in the rest of the text. Especially avoid using brackets around an entire paragraph. Either that information is relevant in that node, and thus can be taken out of brackets, or it should be somewhere else, in another node.
Annotations allow you to add information to this page that would be handy to have on hand during a consultation. E.g. a website or number. This information will always show when you visit this page.