The other part of the title is just as wrong as "unmanned."
Scrolling down the first page of titles, I see references to Terra and WISE. Neither of those spacecraft is a "flagship" or an "interplanetary spacecraft."
And mixing flagship and interplanetary spacecraft is like labeling something "apples and fruits" because a flagship is an interplanetary spacecraft just like an apple is a fruit.
Actually, thinking about it some more, it is even less accurate. You can have flagship missions in all four of NASA's space science mission categories. Hubble is a flagship mission. But what about non-flagship, non-interplanetary spacecraft, like WISE and Terra?
That's why I think the most accurate title is: Robotic Spacecraft (Astronomy, Planetary, Earth Science, and Solar/Heliophysics)
That covers all the categories adequately.