a full STI screen is for HIV, chlamydia, and gonorrhoea

blood test - for syphilis, HIV throat swab - for chlamydia and gonorrhoea anal swab - for chlamydia and gonorrhoea urine - for chlamydia and gonorrhoea

afaik they sometimes tack on general biochemistry (sodium, potassium, etc) to the blood test, as well as some other things like mycoplasma genitalium but these are not standard 3-monthly tests

afaik it’s very rare to test for HSV at all, for various reasons