unsatisfactory
Not good enough to meet the needed standard or expectation.
When something is unsatisfactory, it fails to meet the standard or requirement you need. An unsatisfactory grade means your work didn't reach the level your teacher expected. An unsatisfactory explanation leaves you with more questions than answers.
Something unsatisfactory doesn't have to be terrible or completely wrong. It just falls short of what's needed. If you turn in homework that's rushed and incomplete, your teacher might mark it unsatisfactory because you clearly didn't put in the effort required, even if parts of it are correct.
Notice how this word often appears in official contexts. A restaurant might receive an unsatisfactory health inspection rating. A mechanic might tell you your car's brakes are in unsatisfactory condition and need replacement. A referee might determine that field conditions are unsatisfactory for playing a safe game.
The word carries a sense of official judgment rather than personal opinion. When something is unsatisfactory, there's usually a clear standard it failed to meet, whether that's safety requirements, academic expectations, or basic quality levels.