Can I query a Language Server for arbitrary metadata of a project?

Is there any kind of query I can make to a typical LS that would allow me to get, say, something like all callers of a given function, or the functions contained in some module? All the examples of LS’s and Clients I see in tutorials are more about the interactivity bits (like highlighting certain character sequences), but I’m interested in being able to get metadata about a project. Is looking at LS’s perhaps the wrong direction? Would something like TreeSitter possibly have more of what I want?