To state a question (direct or indirect) in Classical and Medieval Latin, you always need a question marker. These can be either:
- interrogative pronouns or adjectives (e.g. Quis venit?, In quae via ambulat?, Per quod medium probas?, etc.),
- interrogative adverbs (e.g. Ubi estis?, Quousque tandem abutere?, Num venit?, Quaesivi ne indices, Quaesitum utrum Deus sit trinus, etc.)
- The enclitic interrogative article "-nĕ" (weakened from "nē"); also "nonne".
However, Early Latin exhibits total interrogatives without question markers:
- Redis tu tandem? (Plaut.)
- Tu id nunc refers? (Plaut.)
(Note that question marks, and punctuation in general, was a later Medieval development---historically derived from musical pneumas, rather than pragmatic cues---and cannot be understood as interrogative markers proper.)
So, to answer your question: "standard" Classical Latin (what you learn in school) and Medieval Latin always require interrogative markers. Still, not all markers are identical (e.g. Num presupposes a negative answer, -nĕ doesn't presuppose any answer, quando requires a temporally framed answer, and so on), so you must choose well your interrogatives. In sum, "Edisti?" is bad Latin. "Edistine?" is fine.
For those seeking a more "authorative" answer, see e.g.:
Guildersleeve's Latin Grammar (3rd ed., 1903), §§ 453–68, 558 (available here: https://archive.org/details/gildersleeveslat00gild)
Allen and Greenough's New Latin Grammar (1903), §§ 330–5 (available here: https://archive.org/details/allengreenoughsn01alle)
Bassols de Climens, Sintaxis latina (1971), II, §§ 32–40 (available here: https://archive.org/details/SINTAXISLATINA2MARIANOBASSOLSDECLIMENT)
J. Schrickx, "Polar Questions in Latin with and without the Enclitic Particle -ne", in Pragmatic Approaches to Latin and Ancient Greek, eds. C. Denizot & O. Spevac. Amsterdam / Philadelphia: John Benjamins(2017), pp.235–55