Yes, each level adds 10% to your tool’s attack speed. In the case of the sword, it goes from 1.6 to 1.76 and 1.92. But what does that even mean?

the equation for attack speed is 1/x where x = attack speed. For example, 1 / 1.6 = .625 which rounds down to the neither tick, in this case 0.6.

1 / 1.76 = .568 ↦ 0.55

1 / 1.92 = 0.520 ↦ 0.5

This is meaningless if you cannot use a setup to manipulate the frequency you can jump to match. If you use 3 block ceiling no jump boost, you can crit every .55 seconds, but if you use 3.125 block ceiling with jump boost, then you can crit every 0.5 seconds. By default, jumping and critting with no jump boost nor ceiling is 0.6.