We seem to agree that this has good hyphenation:
The question is well answered. The well-answered question illuminates its subject.
So, if well answered precedes the noun, it gets a hyphen. If it follows the linking verb, it does not get a hyphen.
So far, so good, but now try this:
The software is open source. Open-source software is distributed with few restrictions.
The "is open source" does not look quite right, does it? Or am I just looking at it the wrong way? (I admit that it does not look too bad, but is it right?)
Does it matter that answered is a participle, whereas source is a noun? Or that well is an adverb, whereas open is an adjective?
You and I could evade the question by writing "is openly sourced," of course, but that's just wrong, and even if not so, the question as asked would still want an answer. My question regards the principle of the thing.
When should I hyphenate a compound like open source, used as a modifier?