What are the main qualities of a good hypothesis?

iA hypothesis is a proposed explanation for an observable phenomenon. For a hypothesis to be put forward as a scientific hypothesis, the scientific method requires that one can test it. Scientists generally base scientific hypotheses on previous obserations that cannot satisfactorily be explained with the available scientific theories.

These are the essential traits of a good hypothesis:

Testibility

Simplicity

Scope - the apparent application of the hypothesis to multiple cases of phenomena

Fruitfulness - the prospect that a hypothesis may explain further phenomena in the future

Conservatism - the degree of "fit" with existing recognized knowledge-systems

A hypothesis cannot contradict scientific laws.