When it comes to co-workers all I care about is can I trust them to complete the tasks assigned them correctly, on time, and without inhibiting others from doin

When it comes to co-workers all I care about is can I trust them to complete the tasks assigned them correctly, on time, and without inhibiting others from doing the same. I have worked with happy and grumpy people who could and couldn't meet those simple requirements, so I generally could careless about regarding happy vs grumpy.