Recruiters have the reputation of lying to potential recruits and saying just about anything to get them to sign on the dotted line and join the military. Sadly this is true for some recruiters, but definitely not all. Just like any other profession or group of people in the world, there are good recruiters and bad recruiters. Some are under so much pressure to make their quotas that they resort to lying or trying to trick people into joining. I believe these people are in the vast minority though. I personally had a great recruiter that didn't promise me anything he couldn't guarantee and didn't tell me anything that wasn't true.
If you feel like your recruiter isn't telling the truth then do some research online and see if you can confirm what he or she is saying. Most importantly, realize that if what the recruiter tells you isn't written down on paper and in your contract, it isn't guaranteed! For instance if a recruiter tells you that you will be guaranteed a job once you finish BMT but it isn't written in your contract, the job is NOT guaranteed! The recruiter has no control over what job you get at BMT unless it is written in your contract.
Just be smart, ask lots of questions and do your research.