I would suggest that if you can get a copy of the contract you should. Please be aware that the Arabic version takes precedent over the English version so it is important you get it translated.

I would try and find out vis this website or other qatar based ones what the school is actually like. I am a teacher here in Qatar but not at the The Gulf English School. I made the mistake of not contacting teachers at the school I am based at, I have paid the price for my folly.