Tomato varieties that wilted in the Midwest, even badly, always came back when out of the sun. I am now in a much hotter, drier climate. Will I need to shade them if they go limp? Tomato's are grown commercially here in huge numbers in fields and cannot be shaded, of course. They evidently do fine, but they are plum tomatoes whereas mine are Early Girl and Big Boy.
I live in the tomato capital of Canada (Leamington Ontario), sunny and warm but damp. In my experience:
As long as the wilt is limited to the leaves then you should be ok, once the thicker stems begin to wilt you start to stunt growth or cause early fruiting. Not the end of the world but you probably want to avoid it.
I wouldn't bother with shading; I think the issue you'll have to tackle is moisture retention in the soil. You have hot and sunny weather which is a tomato's dream; don't deny them the sun!
A good three to four inches of mulch will go a long way but if it's really dry you may need more than that. I'm not sure what would be available in your area, I've used cedar and other tree mulch, leaves and even straw. You might be able to get coconut husk or something similar. I would spread the mulch as far out from the plant as your vegetable patch allows and increase the amount closer to the stem. I also would recommend a direct watering method, drip irrigation if you have the means or soaker hoses under the mulch would give you better results then just watering from above and help prevent evaporation.
Commercial field tomatoes are not supported in cages but allowed to grow along the ground, which helps to keep the moisture in the soil and may be another option for you. They also water them regularly.