I've already renovated one of the bathrooms, and I’m planning to paint the interior, update the kitchen cabinets, possibly sand the wood floors, build a fence is a corner lot and increase the rent for the room since my tenant is currently renting the entire 3-bedroom, 2-bathroom house for $800 a month.

I'd assume all vanities, lower cabinets, 3to 5ft of drywall and base will all need replacing. 

A complete overhaul of the kitchen and bathrooms, including cabinets, countertops, LVP flooring, electrical and plumbing fixtures.

Job included inside work of leveling floors, installing flooring, paint walls, kitchen cabinets, etc in both units, as well as lay a new driveway, fence the back yard, provide attic fans, and install electric to the crawlspace to add lights and a sump pump.

I would add specific details like pictures of the fixtures/flooring/cabinets.....SKU #s and pictures of everything.

Fix your cabinet with the missing door, remove the stickers from the mirror and window, close the toilet lid, sweep and mop the floors, use a wide-angle lens, and take pictures from an appropriate angle. 

i.e. paint, flooring, cabinets, tile, etc.  

I installed cabinets, painted it, and made it back into a residential rental unit.

For instance, if the contract just says "install kitchen cabinets," it might be unclear whether this includes removal of old cabinets, disposal, or even painting.So what do we need to include in a general contractor agreement?

I'm paintimg all my doors, cabinets, and baseboards semi-gloss, specifically so I can wipe them down easier.