Change the constraints for the $annotation$
variable to:
- Invert condition: false
- Whole words only: false
- Minimum count: 0
- Maximum count: 0
"Invert condition" works like a boolean NOT. When enabled it matches names not like the specified pattern. In your case "Formula" is indeed not like "Column" and matches. By setting minimum and maximum count to zero instead, you're telling Structural Search you are searching for field with zero occurrences of an annotation with name "Column", which should get you the results you want.