I'm curious about contracts that have an expiration date (say, one year) but stipulate you must both agree in writing if you wish to terminate before that date. Any thoughts on how one would approach that scenario? And what constitutes "agreement"-in your nonlegal personal opinion, of course.
No agent can "force" you, contractually or otherwise, to allow him or her to represent you. What can be the case, though, is that you will owe the agent a commission on any offer received or deal concluded prior to the end of the term, depending on the wording of the agreement.
As there is no "standard" agency agreement, just as there is no "standard" publishing agreement, it's impossible for me to be more specific. Most agent-author agreements state that the agent is due a commission on anything ranging from all submissions made to all contracts signed. Of course, there has to ultimately be a contract signed in order for a commission to be due.
Where problems arise is when an author terminates an agent and then a submission made by the agent turns into a deal, perhaps before the author has a new agent, perhaps after. Potentially, the author now has to pay two agents. And while an author may find this unfair, it may simply be the legal reality of the contract. Thus, it is important that you read and understand your agency agreement. And if your agent doesn't work with an agency agreement, consider writing your agent a letter that outlines your expectations of the relationship. There are books with sample agency agreements and you could ask your agent to sign one. Keep in mind that there is likely a reason your agent does not work with agreements and asking one who does not to sign one you present could be a bit like offering a prenuptial agreement to your fiancée.
I advise authors in general to try and clear the decks prior to terminating a relationship with an agent. Try to make the parting as amicable as possible. Unless the agent actually did something unethical or actually illegal, you should try and look at the situation from your agent's perspective. Most agents are working quite hard for their clients and the news that a client wants to leave him or her is shocking.
I once had a client leave me after I spent at least two years shopping his book and got him a two-book deal. The first book came out and became a regional best-seller. Then, just as the second book was about to come out and the first was starting to pick up steam in the foreign markets, he terminated representation. My wife and I had just bought a new house and I was unbelievably busy and stressed. We were trying to start a family. And throughout it all, my first course of action every day was to make sure I was staying on top of this guy's business. And yet he quit me. I was shocked and angry, to be honest, and to this day I simply look at the experience as a lesson in how disloyal a person can be.
So if you are contemplating quitting your agent, ask yourself is it because of the agent or is it because of you? And if it is because of you, then perhaps you should focus on the "you" part of the equation. I have had authors leave me and come back. One even left me again and then wanted to come back again! This says something, I think, about why they may have left in the first place and that it must have had less to do with me, than with them. Very few clients have left me and I take that as a great compliment and I deeply appreciate their loyalty.