in STROBE, they call for writing study design in title. I found it reluctant to write cross sectional study while the title already says prevalence of....
Really indeed in this type of studies it is not necessary to include cross-sectional studies, only to inform about the year of the performance the study
Depends on the journal you are preparing your manuscript for. No need to mention in the title, but often the journal's "Materials and methods" "methods" "Methodology" section requires it.