It is easy enough to estimate the number of seats in a restaurant. 13 tables or more usually means it can hold over 50 people.
Businesses apply for a specific type of liquor license. It is harder to get a bar license than it is to get a restaurant license, so if there is any doubt what type a business holds then it is most likely a restaurant. You can ask a manager what type of license they hold if you want to be thorough.