I think you have to be able to play or realize the full score.

我要能演奏并熟悉整个总谱。

So for example, if you have a two-part essay but you only have time to finish one part, you would not get the full score for task achievement.

例如，如果你碰到了一篇两段式论文，但是你只有时间完成一部分，那么你得完成度就不是满分。