Using terms like "pentatonic" to describe the blues scale can be useful but not strictly accurate.

The actual original blues scale comes from Africa. It neither has a major nor a minor 3rd but an ambiguous not somewhere between the two.

We can usefully compare the blues scale with the pentatonic, but we cannot 'define' it in those terms.

By its very nature it is ambiguous.

So the idea that it is a pentatonic with "other notes added for "spice"." is inaccurate.

A better descriptor would be that it is similar to a pentatonic scale but there are key differences.