Register a *dynamic* tool whose handler may ask the client for more input
on a stateless (MRTR) request. The handler branches on ctx.isStateless:
when stateless it reads ctx.inputResponses and returns either
ToolResponse.complete or ToolResponse.inputRequired; otherwise it may
call the blocking ctx.elicit/ctx.sample. A server that wants to serve
both protocol eras handles both branches here.
Register a *dynamic* tool whose handler may ask the client for more input on a stateless (MRTR) request. The handler branches on ctx.isStateless: when stateless it reads ctx.inputResponses and returns either ToolResponse.complete or ToolResponse.inputRequired; otherwise it may call the blocking ctx.elicit/ctx.sample. A server that wants to serve both protocol eras handles both branches here.