Cooperative means working well with others.
A twelve letter word for working well together is the word "cohesiveness".
Extrovert Gregarious
Volunteering?Working pro bono, of course.
Amiable, Sociable
Anti-social
Taking ownership of mistakes instead of blaming others is an example of being responsible for your behavior. Working cooperatively with colleagues, sharing information, and being reliable in meeting deadlines are examples of working well with others.
Harmonize affiable adapt integrate
excel
You can confirm effective working methods with others in two ways. One is by observation, which will show you how well people together work as a team. The other is assessment. Running company reports on efficiency and production will tell you if your system is working or needs tweaking.
uncoordinated, at 6's and 7's, uncooperative,
To be inefficient implies that something or someone is not working as well as it could be. Synonyms for the word include disorganized, incompetent, or ineffectual.
working well