When she first started (Channel 10 I think), I wasn't a fan of Kelli Underwood, but now I think she is a very good game caller — I think she suffered from the 'no women' policy (unstated, of course).
Enjoy hearing her on the radio — a good strong voice, and calls it as she sees it.
As for whether callers should tell us what's happening, I'm a bit in the 'prefer descriptive' camp — the proliferation of 'personnel' (five and six of them for goodness' sake) — has done nothing for commentary, especially when they set off to talk about their pet topics/interests/shoe size and make no observations about developments on-field in front of them.