[yorwba]

If there are no two words that are only distinguished by tone, it might be unnecessary to mark it in writing, except as a learning aid for people who're not fluent enough in the language to predict this information from context.

E.g. in English, questions are marked by rising pitch, but that intonation is not indicated in writing.

[teractiveodular]

FWIW, Japanese has tonal minimal pairs (ha'shi chopsticks, hashi' bridge, hashi edge), but doesn't bother marking them in (kana) writing. Although the Chinese characters are obviously different.

[vintermann]

> but that intonation is not indicated in writing

Oh?

[jiggawatts]

?