The rule
'Something went wrong' is a status, not a message. A message names what happened, what it means for the reader's task, and the one next step. Three clauses, one sentence if you can.
The inventory
- Form error: name the field, the rule, an example. '+44 7700 900123' beats 'invalid phone'.
- Empty result: 'No components match “xyz” — clear filters or try the tag cloud.' Two exits, stated.
- Load failure: say it is a failure, show retry, and keep the layout so nothing shifts when content arrives.
- Build error in a run log: the model's failure note includes what fixed it — the site publishes these because they are the most-read copy it has.
Tone is accessibility
Screen readers read errors cold, without the surrounding mood. Plain words, no sarcasm, no 'oops'. The reader who hears your error has not seen your friendly illustration.