What is the tone of "there will come soft rains"

"There Will Come Soft Rains," a poem by Sara Teasdale, was published in the July 1918 issue of Harper's Magazine, several months before the armistice that ended World War I.
The narrator speaks of a landscape teeming with life: "swallows circling" and making "shimmering [sounds]," singing frogs, and the flowering of plum trees. Teasdale's verse does not only focus on the day, but also the passage of day into night and the passage of the seasons. She signals these time changes with the actions of the animals ("And frogs singing in the pool at night") and the changes in both plant and animal life ("And wild plum trees in tremulous white, / Robins will wear their feathery fire").
The narrator makes a point of noticing the absence of human life in this territory that has been reclaimed by nature. Teasdale seems to distinguish human life and its efforts—specifically war—as something outside of nature, for nothing natural in the poem knows what had concerned humans for the last four years (e.g., "not one," "scarcely know").
The tone is one that signals nature's indifference to the presence of humans. Even if we were to bring on our own extinction, it would not create the slightest difference in the perpetuation of other forms of life. This is not meant to be negative or even to claim that human existence mars nature in someway. Instead, it is meant to illuminate the fact that we are not as significant as we would like to believe. Life can go on without us.
https://poets.org/poem/there-will-come-soft-rains