Texts have no tone. If it can be read two ways, assume the kind one, or just call.

Written messages arrive carrying whatever mood the reader is already in, so a neutral line from a busy person reads as cold to somebody having a rough day. Both readings fit the same words and the screen cannot tell you which was meant. Choosing the generous one is not naivety, it is accuracy, since very few people are plotting at you. The suspicious reading only feels better informed.

When a message could go two ways, pick the kind one and answer that. If it genuinely matters, ring them rather than running a forensic study of their punctuation.