No, there is no On Summarize event trigger in smart rules.
It is possible to target a location (and I always suggest being more specific than general in smart rules) and use the On Creation trigger.
- Targeting a specific group here, though it could be a broader group, an Inbox, or a database. (Again, I shoot for safety first.)
- Looking only for Markdown docs ending with Summary (again, specific).
- On Creation run the script.
- The sound is optional. I like it for debugging as I know it triggered.
- You may want to add another action to change the files so they’re not continuously matched by the smart rule. this can be a move out of the targeted group, a change of name, etc.