What does an EPA-registered disinfectant actually guarantee?

EPA registration approves the claims on a label, not the product in the abstract. The surface has to stay visibly wet for the entire contact time, or the claim has not been met.
What belongs in a commercial cleaning scope of work?

Every area, a frequency against each, the tasks at that frequency, a named standard, and periodic work on its own lines. A scope you cannot walk and mark pass or fail cannot be enforced.
How is commercial cleaning priced?

Area, frequency and standard. All three resolve into labor hours, which is why a credible number follows a walkthrough rather than a phone call.
Janitorial or commercial cleaning: which does your building need?

Janitorial is recurring maintenance on a schedule. Commercial cleaning is periodic, equipment-led work. Most buildings need both, and the gap between them is where facility complaints start.