A few years back, I was fortunate enough to land an agent for my manuscript. The working relationship was good enough, but admittedly not spectacular. I made the decision to part ways with my agent. The departure was amicable and professional. With a desire to see my story still see the light of day, I rolled up my sleeves and dove back into my MS. I made serious revisions to bring the MS to a place I was proud of (I like to believe that my writing improved over the years my MS was in my former agent's hands).
I'd like to start querying my freshly polished MS and find an agent who believes it can sell. My question is two fold: first, am I already doomed to find a new agent? Is it a major turn off for agents to know that my project was out there with someone else? Secondly, if it's not doomed, do I mention in my query that I once had an agent or do I not mention it at all? I wonder if it's worth mentioning as a means of earning some type of street cred.
Having an agent once before does not give you street cred. Quite the opposite. It gives you baggage.
But the real question is not did you have an agent, the real question is did the agent send out the manuscript on submission.
If the agent sent the ms out, yup, you're done on this one. Time to write a second novel and query that.
If the agent did NOT send the ms out, you never need to mention it to anyone. No harm, no foul.
There's a third category: agents who are so bad at their jobs that even if they send mss to editors, no one notices or cares. How can you tell? When you get the submission list, also ask for the responses from the editors. If there are NONE, you're probably in this category.
There are certainly editors that don't reply even to me (the nerve!) but believe you me, they don't stay on my submission lists for long AND the submission notes that say things like nudge, follow up, firebomb, with dates, for when I called/emailed/hurled reminders of the manuscript.
You are well within your rights to ask for the submission list and editorial replies. This is not privileged information. It's YOUR manuscript.