I had that idea that hints could be useful in bot's responses, so I added them just the previous night.
Now, if possible, the bot will add two hints to its analysis:
The first hint is about what piece to move
The second is about what exact move should be made
Both hints are marked as spoilers and they come from Stockfish 10 analysis with depth around 21.
And you can reveal the spoilers by clicking on them
The hints will be only added to bot's responses when the bot can figure out whose move is it, so if you want to see them, add "White to ..." in the title of a post because currently the bot tries to guess the current player searching for "white/black to ..." in the titles.
The first position analyzed with the hints functionality
Side Effect
As a side effect of this new feature, I implemented Stockfish 10 available as REST API, so if anyone has a decent idea for using it I might consider giving access to this API. I saw that people previously asked for such API but apparently, no such free service existed before.