The duties of congress were assigned by the Constitution. Article I one of the Constitution describes the specific powers of congress.
Alia officia quae delegari possint. (Not an exact translation: "Other duties which may be assigned.")
responsibilities to satisfactory perform or complete a task (assigned by someone)
it is a list of duties assigned in case of emergency on ships
Superogatories are actions that are commendable, but are not required. Duties are required and assigned actions.
gaining supervisor
Concentrating only on your assigned job duties
The early government took all the duties of the king and spread them around to the president, congress, and the senate after the Revolutionary War.
The gods each had their assigned duties. Ares was he god of brutal warfare. That's what he had to do.
The lieutenant governor handles duties assigned by the governor.https://ballotpedia.org/Lieutenant_Governor_of_Illinois
Carried out their assigned task and duties
Police squads carry out whatever activities that they are assigned. For example, last year, a police squad was assigned to take on the job of security for the 2012 London Olympics. Other duties may be carried out as assigned.
There have been 111 Congresses