[jazzyjackson]

> why make them long or random?

To decrease their similarity, make it more difficult to confuse/conflate one word with another.

[bmacho]

But then use the theory of Shannon and Hamming distance to make the words as different as they can be

[foxyv]

Word cadence is also important. We tend to add length to short words and shorten long words naturally until we reach a certain cadence. Longer words can sometimes be easier to say than short ones. If you look at tongue twisters they tend to use short, similar words. By making every word short, you could make an entire language of tongue twisters!

Edit: Also I think Toki Pona uses a reduced character set

https://jansa-tp.github.io/tpcheatsheet/Toki%20Pona%20Cheat%...

[harpiaharpyja]

Toki Pona definitely has fewer phonemes than English (which IIRC has an above-average number of phonemes compared to other natural languages). Having fewer phonemes is important for a language like Toki Pona because it makes pronunciation much more forgiving.