The translation tool on Facebook is powered by Bing if I remember correctly. If you use it, sometimes there will be some funny results, since Bing's translator isn't any good at all.
It also offered automated translations which were also pretty mediocre at best, since the problem was that it detected certain languages and it often detected the wrong language, or it translated it poorly.
Anyways, don't use Facebook Translate. It's pretty crappy and doesn't do a lot. If you want, just get someone on the forums here to translate it, or maybe put it into Google Translate if you want a rough idea of what they're saying.