In our conversation with the client, we found out that these "items" can be subdivided into "tasks", "requests" and other elements. An understanding of this hierarchy was essential to keep to the logic of the translations in those cases where it was not obvious from the text itself:
{{flow_name}} - {{action_user}} assigned {{item_id}} to you.
{{flow_name}} — {{action_user}} назначил(а) вам объект {{item_id}}.
In order to keep the translation grammatically correct, it was necessary for us to add an explanation before the placeholder, because the Dative case in Russian would have required case changes in the placeholder itself (at least for Feminine nouns).
We knew that in this system, the object could be a task, so we understood that the use of the verb "assign" — "назначить" remained appropriate. However, the concept of an "object" is broader than that of a "task", which meant that the safest option was for us to use "object" as a complement.