Not very useful definitions are by definition more useful than useless definitions.
If a person lobs avalanche prevention ordinance upon an unstable mountain slope thereby preventing the demise of the hikers I invented earlier, that person's actions might be said to have affected the behavior of the mountain.
If the person lobs ordinance after the invented hikers have met their fate, that person may well change the mountain slope geometry in such a manner that unique unstable accumulations are no longer physically possible [while others may be].
Clearly neither seems like a case where there is moral agency in the mountain. We get moral agency when the person lobbing ordinance onto the mountain slope is doing or forgoing the activity in the presence of hikers.