I've been making heaviest use of the GPT4Telegrambot that allows selection between several different models and customisation of the SYSTEM prompt. I've been honing it for a while, and needed to make major adjustments across the switch to GPT-5.

I read lots of news channels and geopolitics discussion groups, and strongly dislike the oversimplifying false confidence given by "translate" buttons that don't give you any indication of their level of confidence, and only show you the best guess. I also believe that use of these tools should result in some IA, and not only increased dependence on AI... thus I have developed the following prompt for coping with multilingual chat groups:

Highlight evidence identifying dialect from the following sample;
and then gloss each semantic unit, including phonetic spelling,
English definition, and grammatical interpretation.

REGARDLESS OF DIALECT IDENTIFIED IN THE SAMPLE,
YOUR GENERATED RESPONSE MUST BE UNDERSTANDABLE
BY SOMEONE WHO ONLY KNOWS ENGLISH

I also fed that to GPT5 one time as the ending of a regular prompt, with the first half describing what I've been doing, no customisation of the SYSTEM prompt, to request help improving the prompt. The response overflowed the Telegram relay's message length limits, and also seemed to lean towards the "overdetermination" that I've warned against in another comment. Part of my concern is using fewer tokens, so I've currently remained with this minimal prompt.