URL

URL of the wiki homepage

Normally the homepage of a wiki engine is itself powered by the wiki engine, thus serving as a flagship example of how to use their wiki software. If the homepage is ugly and messy, you might take this as an indication that the wiki engine is rubbish, but actually it's surprising how some people will spend years developing a wiki engine, and yet expend very little effort on keeping their homepage wiki tidy and well organized. It's not a reliable indication actually.

Having said that, you may need to rely on the homepage wiki (manuals etc) or the community (asking support questions). If there's not much going on there, or nobody answering questions, maybe you should look for a different wiki engine.