Check around the site to see where that site gets its etymology. Then, once you find that listing, track down where that listing got its etymology. Go as many layers as you can.

We've actually had a number of discussion about this site in the modteam here. The issue is that while it is in general a good resource, there are a number of issues. Every once in a while you will come across something that's not quite accurate, but which you wouldn't necessarily know was a problem unless you were already familiar with the etymology.

Generally it's a good place to start. As /r/The_Alaskan said it's always good to check up on the sources given. In that sense treat it like you would Wikipedia.

99% of the time you'll be alright trusting the etymologies, but if it's something important be sure to check against other sources.