For real property, you cost basis is anything that improves the real property (land and permanently attached structures). So that includes the cost of landscaping, adding a paved driveway, and so on.
Allowable adjustments to basis are listed in publication 523.
https://www.irs.gov/forms-pubs/about-publication-523
Tools would never be includable in the basis of the property. If they are personal tools, that's a personal expense. If you were in business of building houses, they would be assets of your business and would be a depreciable expense against your income.
You didn't mention inspections and permits, you can can include those costs.
I'm not sure about utilities. If this was always intended to be an investment, there is a way to capitalize (add to cost basis) your carrying costs (property taxes, hazard insurance, utilities) but that was placed on shaky ground by the 2017 tax reform law, and in any case, would have required attaching written statements to each tax return when you had costs to capitalize. So it would require filing amended returns and, as I said, the procedure is probably no longer allowed. Without the ability to capitalize expenses, you can deduct property taxes as a schedule A itemized deduction (subject to the $10,000 SALT cap), but hazard insurance is not deductible or a cost basis adjustment, and I think the utilities probably go away, too. (For example, if there were days or weeks the property was empty and not being worked on, due to the health issues you mentioned, those utilities are not being applied to property improvements--at best, they are maintenance expenses keeping the property as-is so it doesn't deteriorate, but that's not allocable to the cost basis.)
