So there’s been a run of news of badly behaving agents of late which has put me in mind of the challenge of ID'ing a bad agent from the outside, and the distinction between “bad at the job” and “bad for you.” (thread ahoy!)
Any agent who’s been doing this for more than a couple years likely has former clients. Sometimes those are friendly exes and sometimes not. It happens! People’s careers and needs change on both sides. And not everyone is a good fit forever.