no the advantage of graphql is that the caller can limit the response to only the information that they need. in a REST API the caller has to filter out the extraneous information. using LLMs to do the filtering uses up context window

This is not fully true.

Most agents will use curl | jq to slice what they need (assuming a known API)

Yea- its just a matter of whether the work is delegated to the client or offered by the server. Making sure what is served is in a really quality schema is generally the most efficient path- ime