foreign credentials evaluation for unrelated bs degree

Congrats aseke
I have a quick question for aseke and nelsona

Does the TN letter have to say the duration of employment to be 3 years for you to get a TN for 3 years?
If I only signed a contract for 1 year, and the TN letter also states the duration is for 1 year, would I only get a 1 year TN visa?