Essentially an Agent is an individual or organization which matches up teachers and schools. They approach schools and promise to find them English teachers for a fee. They then advertise and get in touch with teachers who want to work in the country. They then recruit some of those teachers and send them to the schools they are acting for.
This is the theory. In practice, however, there are a number of issues and sometimes problems with agents. In the TEFL industry they tend to have a poor reputation amongst established teachers, but at the same time they can be very useful for new teachers.
An agent can help teachers in several ways:
An agent, therefore, can be very useful for a new teacher.
If you have several years experience teaching in, say, China, then you will know your way around, you'll understand some of the difficulties of living and working there, and if you have a problem you will have your own friends, colleagues and support network in China to help you.
But, if you are a new teacher and this is your first experience in a new country, you may well feel alone and abandoned. An agent becomes, therefore, someone to turn to if you have a problem.
An agent charges a school to find them a teacher. Reputable agent do NOT charge teachers to find them work. If an agent asks you for money, simply walk away. You should NEVER pay anyone a single cent to find you work; if you do, you are most likely being scammed.
So, an agent charges the school to find them a teacher. This means that the agent, essentially, works for the school. And this means that if there is some kind of contractual dispute between the teacher and the school, the agent is likely to take the side of the party which pays them: the school.
On the other hand, an agent wants to keep both parties happy because if the teacher leaves the school, they won't get paid. In this respect they will try to resolve issues, but if it comes to deciding between you or the school, the agent will most likely choose the school.
Remember also that as agents make their money from schools, some of them are prepared to deal with schools which may not be the best. Some agents are very scrupulous here and will only deal with high quality schools which offer good conditions and a reasonable salary to their teachers; other agents will supply teachers to any old school which asks, regardless of reputation or conditions.
If you do have a problem with the school, it's obviously first best to approach the school. If there's still an issue, without an agent you are left with few alternatives. If you do have an agent, however, you can ask them to try and sort out the problem. Most agents are at least willing to smooth things over and try to find a compromise.
There are good agents and bad agents. If you are an experienced teacher who knows the ropes of a country then you are probably able to do without the services of an agent.
However, for new teachers in a new country, an agent can provide a backup if things go wrong. The other thing to consider is that you will have less control over where you are sent and may well end up teaching in a small town when you asked to work in a big city (which may not be a bad thing in itself, but that's for you to decide).
Before selecting an agent, do a search online for them and see what others say, but do bear in mind that people who have used an agent and found them good tend not to post, whilst those who have a gripe do.
Finding Work - a general look at how to find work in the TEFL industry.