Questions about staffing agencies

Hi everyone, I'm a recent May grad so I've been on the job search for two months now. In that respect, I feel kind of vulnerable whenever recruiters approach me for something. I was wondering if anyone had any advice on what I should really do to determine whether a staffing firm is trustworthy or not. Just recently in particular I was approached by Astrix Inc. and the person on the phone was very amicable and honestly seemed like she was genuinely trying to help me. It's this that I'm concerned about, it really just feels too good to be true so I'm being wary. Maybe I'm just being overly cautious, but has anyone here had any prior experience with Astrix or a similar staffing agency? Are they good entities to put my faith in?

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