A standardized chime in the beginning of the phone call could serve to alert humans as well as AI agents that the party they are talking to are an AI, eliminating the first part of the conversation.
https://en.wikipedia.org/wiki/John_Draper#Allegations_of_sex...
1: https://www.reddit.com/r/etymology/comments/13hc2gw/why_was_...
Isn't that exactly what happens with every IVR (phone menu) system?
See everyone using their own LLMs to write paragraphs that will never be read and only summarized by an LLM on the other end. We're achieved negative compression.