Currently, access to the Item Modification by Age tool is determined by the items_batchmod permission. In a Consortium setting, a common scenario is to restrict item editing, including batch item editing, to staff users of the item owning library. This is done via Library Groups and the standard edit_items permission. However, the Item Modification by Age tool does not restrict the items.homebranch condition, allowing users of any library to define a new rule for a library they don't belong to and whose items they don't own. Breaking the tool permissions into two separate permissions would solve this issue.