The short answer
Send a wide view of each work area, a close-up of the surface and problem, and a photo of the access route. Add your postcode and approximate dimensions in WhatsApp.
Start wide
A close-up of a stained slab says little about the size of the patio or its surroundings. Stand back to show the complete area, then take another view if a corner is hidden. For the house, show each elevation you want included. Take roof and high-gutter photographs from the ground; the provider can arrange an inspection if more information is needed.
Show the material and its condition
Photograph joints as well as the main surface. Include loose pointing, cracks, flaking finishes or previous repairs in the brief. If you know the product brand, material or installer, mention it. Do not guess that a surface is sandstone, resin or a particular render system simply because it looks similar to a photograph online.
Explain the route to the job
Show a narrow side gate, steps, a shared passage or a conservatory beneath upper windows. Tell us whether equipment can reach the rear without going through the home. Mention parking arrangements, an outside tap if present, and any time restrictions on access. The provider should confirm what supplies and space the job actually needs.
Add the information a photograph misses
Give the approximate length and width of paving, the number of storeys and the services you want. Explain when an overflow or stain appears and whether you have tried any treatment. For bins, say when they are collected and whether you want a one-off or recurring clean.