"Furnished" is not a defined standard in Dubai, and on a villa the gap between what two landlords mean by it is enormous. Establishing exactly what is included, in writing, before you sign is the whole job.

What furnished can mean

Fully furnished with an inventory: beds, sofas, dining, white goods, and often crockery and linen. You arrive with suitcases.
Furnished: usually the large items only. No kitchenware, sometimes no washing machine.
Semi furnished: in practice this often means white goods and wardrobes and nothing else.
Kitchen equipped: the appliances are there, the furniture is not.

Ask for a written inventory with the tenancy contract. If the landlord will not provide one, that tells you something about how the rest of the tenancy will go.

What the premium should be

A furnished villa costs more per year than the same villa unfurnished, and whether that is good value depends entirely on how long you are staying. Over a year or two it often is, particularly if you would otherwise be buying furniture you then have to sell. Over three or more years you are usually paying more than the furniture is worth, repeatedly.

Where furnished genuinely wins

A first year in Dubai, before you know which community you want to stay in.
A fixed term posting.
Anything under a year, where you are likely in the licensed short let market anyway.

Where it does not

A long stay in a family villa. You will live around someone else’s choices for years, and villa furniture takes heavy wear. Unfurnished plus your own purchases is almost always cheaper over three years and considerably more pleasant.

What to check before signing

The written inventory, photographed on the day you move in.
Who repairs or replaces a furnished item when it fails, and how quickly.
The condition of the air conditioning, which matters more than any sofa.
Whether you may remove or store items you do not want.
How the deposit treats wear on furniture, which is where furnished tenancies most often go wrong at the end.

Tell us how long you are staying and we will tell you whether furnished is worth it in your case. How monthly villa rental actually works in Dubai covers the payment side.