Defining a Tenant in lease contract

[Chris Lohmeier]

Hello BiggerPockets, I’ve been absorbing all I can for this community for a year or so now but have finally came across a question I can’t seem to find the answer too. 

I'm in the process of picking up my second SFR rental property, so I'm revising my lease. I'd like to add a section that basically defines what a Tenant is to spell it out for the current tenant. This way they would know that they can't invite someone else to live with them without them being vetted by me and needing a new lease signed with everyone's names on it. I'm not sure how exactly I should be describing an additional Tenant.
Here’s what I have so far:

ADDITIONAL OCCUPANTS. Tenant’s guest will be considered an additional occupant if they are eighteen years of age or older and any of the following occur: Guest spends more than three nights a week on average over a one month period at the Premises, Guest is on the Premises without Tenant supervision for more than four hours during 4 consecutive or nonconsecutive days during any week, Guest is given a key to any door of entry on the Premises. Additional Occupants may be added to the Premises only after the additional occupant has been approved by Landlord, a new Agreement has been signed that includes the additional occupants name as a Tenant, and if the additional occupant does not cause the Premises to exceed a total occupancy limit of ____, as required by state law.

I feel like I could use better descriptions for the actions that turn a guest into an additional occupant, but I don’t want my standards too tight that someone can’t have family visit them from out of country for a couple weeks. Has anyone else went down this path before, or am I just being over careful in my lease?