To execeute tests with tox just invoke tox or tox -p. The tox-poetry plugin will read pyproject.toml and handle the envs creation. In case of a change in the dependencies you can force a recreation of the envs with tox -r.
One might also want to just run a specific testenv like: tox -e coverage.
To reduce the noisy output use -q like: tox -p -q