You could probably use find/change to add the space.
I'd try the followng GREP:
\.(?![\d\s[:punct:]]) which I believe will find the periods not followed by any type of whitespace, a digit, or other punctuation (you might not want to change those elsewhere in the document if your search scope is not narrow enough to limit it to the descriptions, and even then there might be cases that would apply).
Replace with $0<spacebar>
For clarity, <spacebar> indicates you should type the space.