Humble, non-boastful, modest, meager, or self-effacing.
Submissive, dispirited.
(of horses) To tame; to break.
Capable of being easily led, taught, or managed.
Easy to deal with or manage
Capable of being shaped; malleable.
Sufficiently operationalizable or useful to allow a mathematical calculation to proceed toward a solution.
Algorithmically solvable fast enough to be practically relevant, typically in polynomial time.