They can tell you all about Pluto's mass, shape, orbit and so forth. Whether it is a planet or not is a matter of definition and hence essentially arbitrary. It's a human classification category, nothing to do with the object itself.
If we wanted to, we could reclassify any sun-orbiting objects smaller than the earth as "non-planets" and Mercury, Venus and Mars would promptly drop out of the "planet" category.
Beat me to the punch, thanks.