The MCP initialize response has both a description field and an instructions field, but in reality there aren't any clients I know that make use of these fields. Even some official SDKs do not expose these fields.

It will be nice to provide some guidance in the spec on:

• How these fields should be set by the server and how the clients should use these fields.
• What's the difference between the two

If we require servers to describe clearly what they are used for in these fields, clients could use them to determine whether to load these servers to LLM context or not (aka progressive disclosure).