I want to create a homebrew feature that will allow a character to take specific action on advantageous modifiers when lacking in primary means (low ability score or lacking skill/tool proficiency)
I considered using existing features' wording as replacement, but they come with limitations, and narratively such feature should be an attack. Examples of limitations would be "make an ability check using your spellcasting ability" from Counterspell that doesn't add proficiency modifier or any "Roll d20" which couldn't be modified at all.
What changes when I substitute an attack in place of ability check, other than obvious different ability and proficiency modifiers? What mechanics apply to one, but not the other?
Class feature that modifies shove special attack
You can use a bonus action to try to shove a creature within 5 feet of you with your shield, making Melee Spell Attack instead of Strength (Athletics) check against opponent's Strength (Athletics) or Dexterity (Acrobatics) check, not their AC.
Example 2: Class feature / feat that allows lockpicking with fist rather than doing Dexterity (Thieves' Tools) check.
As an action you can make an unarmed attack against lock, treating lockpicking DC as AC. On hit the lock opens.
(example phrasing subject to change)