It’s a disingenuous question: the answer is obviously yes. Consider, though, how often you write one when you might not need to, and a reader might be able to extract the necessary information more quickly.
(No shade meant to the paragraph. I love paragraphs.)
|I’m explaining how to do something.||Use a list of steps.|
|I’m persuading someone to do a thing.||Sure, you can use a paragraph–also consider bullets, or a table.|
|I’m creating descriptive reference information.||How about a table or diagram?|
|I’m teaching someone a skill.||OK, but maybe give them hands-on activities?|
|I’m clarifying how something works.||Maybe, but diagrams are good too.|
|I’m explaining why something does something.||Go for it! Paragraph!|
|I’m describing something.||OK, but:
1. Make sure you have a good reason to describe it at all!
2. Would a picture or diagram help reduce paragraphiness?
|I’m describing a user interface.||You poor thing. Here is some whiskey.
Please don’t write paragraph-length descriptions of a UI. If you can’t have screenshots (lots of reasons why not), your UI is truly baffling, and the UI team can’t incorporate field descriptions on screen, how about a definition list or table?