Hiring is tricky, most standard recruitment agents are nothing more than order takers ... They just tick off skills which isn't helpful, I have found 2 Recruiters that understand our company and our culture and have the ability to find suitable fits.
That said it took working with 15-20 different agenecies in 14 years to get these 2.
One bit of advice though, the good ones usually run their own show or are principal players, they don't focus on skillset much, they write very creative job ads to hook the right candidate, they spend a long time talking to you about your business, goals, pain points etc and often suggest better alternatives to what you are asking for.
If all you have is an order taker then, most bad experiences come from bad upfront breifs. I wrote a page of dot points decribing personality traits, goals, interests etc as the brief to recruiters ... The ones that questioned me on this list I gave a chance to.