The Bug:

minecraft.used:minecraft.shears doesn't increase when carving a pumpkin.

Steps to Reproduce:

• Create a scoreboard objective for tracking the use of some shears and set it to display on the sidebar.

/scoreboard objectives add UseShears minecraft.used:minecraft.shears
/scoreboard objectives setdisplay sidebar UseShears

• Place down a pumpkin.
• Right-click it with some shears to carve it.
  →  Notice how the scoreboard doesn't increase.