Whilst EAs do seem to have a habit of calling any ground floor room with obvious purpose an additional bedroom, I do agree with @ShyMaryEllen - the important consideration is how the potential buyers plan to use the space.
We once purchased a fairly odd house (dating from the Tudor period, but dismantled and rebuilt in a new location in the 1930s and now resembling a Tudor chalet bungalow!) that had two rooms plus an ensuite on the first floor and a whopping six - plus kitchen and two bathrooms - on the ground floor. The EA marketing the property called everything except the kitchen, bathrooms and one reception on the ground floor a 'bedroom'.
DS had just gone to university so there were just two of us at home most of the time, with the occasional overnight guest or two, and therefore we had no need to use all of those additional rooms as bedrooms. We used them as - main living room, dining room, breakfast room (it led off the small kitchen so was kind of like an overflow of that space with dresser etc), office, music room, guest room for my elderly parents.
If we'd settled in that location and not sold after three years, we were planning to knock through two rooms to make a larger kitchen and convert another room to a walk-in pantry.
When we sold, we got our EA to label most rooms as we'd used them, with a couple as 'reception 3/bedroom' etc. Our buyers had six DC so did actually use them as bedrooms.