DogHugger nailed one of my pieces of advice. Mentioning MC details are only needed if they relate to the plot and conflict that is going to draw readers and agents in.
Who is your MC, give one or two quick and fast descriptors then move on to what they want, what's in his/her way, and what they need to do to get it.
Loglines for films are done in almost the same way, so check this link out:
So in the end, you should have something like:
Nineteen-year-old Freddie Jones wanted/needed to _________, but one magical drink turned him into a frog, and to get his life back he must _____________.
All of those juicy details will come afterwards.