What should a solar-battery backup quote spell out?

A battery total isn’t very meaningful unless the proposal explains what stays on during an outage. Does it identify the backed-up circuits and state the runtime assumptions behind the proposed battery size, or just give a storage capacity and a price?

I’d also want to know whether the price includes the inverter, transfer equipment, installation, and any panel changes. And if the system has solar panels, the quote should say whether they’re designed to recharge the battery during an outage; I wouldn’t assume that from the presence of panels alone. What details have helped you compare a battery proposal fairly with a solar-only quote?