I have been asked what good looks like at the staff level often enough that I have a reasonably clear answer. The honest version is not a list of skills. It is a description of how a staff TPM occupies a room, makes a decision, and handles a situation that has no clear playbook.
A staff TPM walks into a room with a point of view. Not an agenda, a perspective informed by real knowledge of the business, the technical constraints, and the organizational dynamics. They offer that perspective directly and update it when they hear something that changes it. They do not wait for consensus to form before contributing, and they do not hold their position when the evidence changes.
A staff TPM makes decisions that are not theirs to make, because nobody else is making them and the program needs them made. They document the decision, name who was consulted, and hold it. That kind of initiative at scale, repeated across programs and over time, is the thing that gets noticed before a promotion is discussed.
A staff TPM also knows what they do not know and says so specifically. Vague uncertainty is a senior behavior. Staff-level uncertainty is named: I do not know the regulatory timeline for this market and I need to find out before I commit to a date. That specificity makes the unknown workable rather than uncomfortable.
The last thing, which is also the hardest to articulate, is presence. A staff TPM makes the organization feel more capable when they are engaged with a problem. Teams feel clearer. Decisions feel closer. The path forward feels more navigable. That quality is the compound result of all the others, and it is what people mean when they say someone is ready for the next level.