There is so much you need to learn. Looking at the breaker is only one indication of service. You need to be aware of your wire sizes and the breaker that you need with each. When it comes to the main supply, you look at the (1) main breaker, then you look at the (2) main supply wire, and then the (3) box rating. Just because a breaker says 200-amp, it does not mean it is a 200-amp service if the wire coming in is a 2-awg copper (125-amp), this is a 125-amp service and acts as if there is no true main at all, it is just a shut-off switch. Or, if it is a 2/0-awg copper (200-amp) with a 100-amp breaker, the system is a 100-amp service. Or, if the service box is rated for 100-amp service and you have a 2/0-awg copper coming in with a 200-amp breaker, the bus bar can melt down, arch, cause a fire, etc. because the box is not rated for this type of power. Another thing that is common is to have a 12-awg wire going into a 40-amp breaker, a 14-awg into a 30-amp breaker, etc. - fire hazards. What I am trying to say is that as a home inspector, the electrical service can mean life or death to your client and you need to know what wire goes with which breaker. Don’t go just by the number on the breaker, but know the wire also, does it belong? If something doesn’t look right, research it; otherwise, you may want to look for another job because as home inspectors, we are here to help our clients not only with the most important purchase that most will ever make but to protect their lives and well-being also. I hope you can hear what I am saying and I wish you all the best.