Start with the type of appointment
An inspection, a sweep and an examination prompted by damage have different purposes. A sweep may find little residue, or may find a deposit or obstruction needing work outside the original quote. Ask what service was agreed and what observation led to a change. A glance up from the hearth is not a complete account.
Ask where access actually reached
An insert, a bend, a damper or a roof access restriction can affect the practical route. CSIA discusses homeowner concerns about cleaning from the top or bottom and the need for an appropriate inspection. Ask which surfaces could be seen and which were reached by the chosen cleaning tools.
Turn an access limit into a next step
If an area could not be assessed or cleared, get its location and the reason. Ask what additional access or equipment would resolve the issue and whether the fireplace should remain unused in the meantime. You should not have to climb onto a roof or dismantle an insert to evaluate the invoice.