I am, now and on occasion, a hiring manager. Naturally, every freelance recruiter wants to be my friend. They often start cold calls with a description of a person's technical abilities, and then ask if I would be interested in interviewing that person. When that happens, I ask them to define one of the buzzwords that they have just used. "Could you tell me what 'big data' means?" or "What's the difference between AW…
You can scour LinkedIn day and night for candidates, but especially in software engineering, finding inclined candidates is a much narrower task than finding an engineer with big data experience and experience with GCE.
Any recruiters I work with only need to understand how much they need to understand about technical skills to deliver me a workable and most importantly inclined pipeline. It's my job to educate them about subtleties in my requirements.
Edit: I should note, these are recruiters I've worked with on an ongoing basis. With cold calls, if they lead with a frag grenade of skills and buzzwords, that's just a bad pitch imo.