If the score is 0 in the Aeries grade book, the score returned by the above endpoint is the maximum points. For example, the grade below in the Aeries grade book says 0 out of 0 points. The response from the API is maximum points.
{
"PermanentID": ####,
"GradebookNumber": ####,
"AssignmentNumber": 4,
"DateCompleted": "2020-09-16T00:00:00",
"IsMissing": false,
"PointsPossible": 18,
"PointsEarned": 18,
"NumberCorrectPossible": 18,
"NumberCorrect": 18,
"Mark": "18",
"PercentCorrect": 100,
"RuleNumberApplied": 0,
"IsRuleReplacingScore": false,
"RuleReplacedScore": 0,
"StandardScores": []
}