Tokina 12-24 lens

I have received a Tokina 12-24 f/4 DXII lens as a Xmas present.I am a very beginner in photography with a Canon Rebel XSI.I already have a Canon 17-85mm lens and a Canon 55-250 mm.I am curious if I will get a good use with the Tokina?I know its a wide angle lens and its preferred for landscape photography but will I be able to use it in town,NYC or other and photo with people incl. as well?Should I hold on to it or not and do with the lenses I already have?
Thanks for replies and any informations i can get
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georgep