When trying to figure out how long of a lease to sign with your tenants usually depends on the situation. You as the owner of the rental property have the authority to decide what type of lease terms you would like to offer. If you are not sure if you want to rent out your home for the long term then you may want to only offer 6 month leases. The typical lease term is 12 months, which is what most tenants look for, however there are still plenty of tenants looking for shorter tem leases as well.
So the answer to the question is a 6 month lease too short. The answer would be no. The reason being that there are plenty of renters looking for short term leases, and deciding to rent a property for 6 months, means that if your tenant renews for another 6 months and you rent your property out initially in the summer you will always be able to relist it during summer months which is the prime renting season to get your rental property rented fast.