Quality tools gives you better uses from tools and weapons in Minecraft. It randomizes the quality whether you find them or forge them and each ranges from awful to incredible in terms of durability and strength.
If you hover over the items you’ll get a brief description of its new abilities. You could gain an increase in attack and dig speed. Or you could have an increase in attack damage but a decrease in dig speed.
And you could even strike a series of bad luck with broken or worthless tools that offer no good benefits and are better off thrown away.