why do you think the article doesn't mean copper alloy?

The only use of the word 'pure' is right before iron.

it's pretty common to refer to Otzi's axe as a 'copper axe', right in the wiki page: "Ötzi's copper axe was of particular interest.". but it's 99.7% copper. It contains other materials

I really dont understand jumping from 'copper tools' to 'pure copper tools'. Otzi's axe was maybe both an example of his mastery of the profession and a useful tool (it shows signs of use and rework).