A good thesis is a complete sentence that defines your argument.
A good thesis addresses your opponents’ views in a concession clause.
A good thesis often has mapping components or mapping statements that outline your body paragraphs. These mapping components are written in correct parallel structure.
A good thesis avoids the obvious and instead struggles to grapple with difficult and complex ideas. As a result, a good thesis feels fresh and insightful to the point that the writer actually WANTS to write the essay. When your thesis feels stale, you don't want to write your essay; rather, you merely SLOG through it like a dreadful chore.
A good thesis embraces complexity and sophistication but is expressed with clarity.