The first parameter of the /clear command must be changed to be required

The current /clear command removes all of your inventory if there are no parameters. This may result in unintended permanent loss of the item due to mistakes such as typos.

To solve this problem, you need to change the first parameter displayed as [<targets>] to <targets> and make it a required parameter.

With the above changes in place, to remove all of your inventory you will need to type: /clear @s