Patrick and Sheila are quite right with "prudently" or "circumspectly", with the meaning of "taking every pertinent aspect into consideration". For some reason though, we rarely see these two words used in HR performance assessment contexts. Much more usual would be related terms like "carefully", "diligently", "thoroughly", "conscientiously", "considering all the aspects of the task" or "taking every aspect of the task into consideration".

We could write:

"Sie übernimmt nur Aufgaben, denen sie sich gewachsen fühlt, und löst diese dann sehr umsichtig und erfolgreich…"

=

"She only accepts / takes on tasks she is confident she can handle. She then carries them out very successfully, taking every aspect of the assignment into consideration…"

Or similar blah-blah…

HTH

Dan