feat(macros): auto-generate get_info and default router (#785)

* feat(macros): auto-generate get_info and default router

* docs: simplify examples and docs with new defaults

* feat(macros): add tool_router(server_handler) to elide separate #[tool_handler] impl

* docs: add Tools section to README and simplify calculator examples with server_handler

examples/servers/src/common/calculator.rs

@@ -1,11 +1,6 @@
 #![allow(dead_code)]
 
-use rmcp::{
-    ServerHandler,
-    handler::server::{router::tool::ToolRouter, wrapper::Parameters},
-    model::{ServerCapabilities, ServerInfo},
-    schemars, tool, tool_handler, tool_router,
-};
+use rmcp::{handler::server::wrapper::Parameters, schemars, tool, tool_router};
 
 #[derive(Debug, serde::Deserialize, schemars::JsonSchema)]
 pub struct SumRequest {
@@ -23,18 +18,10 @@ pub struct SubRequest {
 }
 
 #[derive(Debug, Clone)]
-pub struct Calculator {
-    tool_router: ToolRouter<Self>,
-}
+pub struct Calculator;
 
-#[tool_router]
+#[tool_router(server_handler)]
 impl Calculator {
-    pub fn new() -> Self {
-        Self {
-            tool_router: Self::tool_router(),
-        }
-    }
-
     #[tool(description = "Calculate the sum of two numbers")]
     fn sum(&self, Parameters(SumRequest { a, b }): Parameters<SumRequest>) -> String {
         (a + b).to_string()
@@ -45,11 +32,3 @@ impl Calculator {
         (a - b).to_string()
     }
 }
-
-#[tool_handler]
-impl ServerHandler for Calculator {
-    fn get_info(&self) -> ServerInfo {
-        ServerInfo::new(ServerCapabilities::builder().enable_tools().build())
-            .with_instructions("A simple calculator".to_string())
-    }
-}