equipment damage – Is this a good rule to know when i can shoot the sun? “if the sun is not too bright to look at with naked eye, then it’s not too bright for DSLR”

Most of what i have read about this, say that whether or not the sun is bright enough to harm the DSLR, depends on a lot of factors e.g. time of day, cloud cover etc.
For example, i am quite sure , taking a photo of midday sun would be quite harmful for DSLR. But shooting a sunset probably is okay.
So, exactly how harmful is the sun for DSLR ? Is it more of a “its okay once in a while, but do not do it all the time” kind of thing ? What if i shoot a person with the sun in the background? Will that damage the DSLR?

Also, i understand that the human eye’s safety threshold is lower than that of DSLR.
If that is true, then is “The sun is not too bright to look at with naked eye” a sufficient condition to determine when it is Okay to shoot it with DSLR ?
What about with cellphone cameras ?