Before I had my agent I sent the same proposal I sent to agents to publishers, it worked out for the most part. However, after I landed an agent I saw his pitch was quite different than mine.
I assume it was the only proposal he had sent them regarding my book because I wasn't sent anything but that forwarded email, it was less than a page and included my conversation with an editor at the publishing house he was subbing to, a conversation I had before I landed my agent.
It was basically a pitch in my opinion. A blurb about my book, a comparison to one of their books, a bit more and then the conversation between the editor and I which included her saying that she liked the book idea and the writing.
Recently after my agent did a followup the editor did say that she hopes to sit down with my completed manuscript / proposal by next week. Now I assume the proposal is my agents pitch rather then something I have not yet seen.
However, I might be wrong and he may have sent a traditonal proposal.
Before this agent I had an agent write a proposal for me that would be sent to publishers if I had signed with her. She let me look it over to add / edit things but to my understanding she would be writing the majority of it, it read the same as my proposal I sent to agents / publishers in the first place except better written and more professional.
Outline of content, marketing, target audience, books in comparison, summary, credentials, why I should be the one writing this book, things like this. I recall it being around 3-5 pages, not near 10-50.
I'm still a bit confused as to if this is considered a "proposal" by definition if it doesn't fit the usual industry standard. However, I know my current agent knows what he's doing so if he decided to send just a page, he knows best.
I could be completely wrong and maybe just haven't seen my agents proposal to them, if it sells I'll have to ask
Still on sub until next week (?)