The only time I ever described an alchemists set in my game was when they encountered one in a dungeon.
It was a huge workbench about 10 feet long by 3 feet wide, covered in flasks, retorts, distilling coils, vials, flasks and a huge network of glass tubes connecting all of it, sort of like a mad scientist's chemistry set. Beneath the workbench were drawers filled with more supplies and glassware, as well as myriad jars, vials, bottles and pouches of just about every chemical you could imagine could be created with pre-renaissance level technology, and plenty of herbs and minerals of all kinds as well. To the side was a barrel of water and a small oven for heating. There were workbooks and textbooks on pedestals for reading as well as a small bookcase, and wall charts of formulae and compounds, and a supply of paper, quills and ink.
They decided to pack it all back to their own base, I ruled it was a masterwork alchemists lab, although they had to pay 20% of the cost of it to make up for breakage during the fight in that room during the dungeon crawl. It's now in a small building in their keep, about 20 ft by 20 ft, and is mostly just referenced in passing when they create a potion or decide to make something with Alchemy.