For me it has to be well taken photos and a floor plan you can actually read. It still amazes me that EAs using Rightmove use such awful pictures and if they upload a floor plan at all it is often so small you can't even see the dimensions.
Yes, it's intensely irritating.
And if it's a leasehold flat, I want to know length of lease and how much the service/maintenance charges are.
Amazing how many EAs don't include such basic info, and don't even have a clue when you phone to ask.
I looked at a leasehold flat last year where the vendors own the FH of the whole building, so it'll be a new lease.
When I asked how long it'd be, EAs said vendors hadn't decided yet.
I pointed out that this was the sort of thing potential buyers need to know, not a minor detail.
A year later, that flat's still on the market (reduced a whole 1.5%) - and the EAs STILL haven't a clue how long the projected lease is going to be.