Rebuild the docs around tested examples; shrink README.v2.md to a pitch (#2978)

docs_src/lowlevel/tutorial006.py

@@ -0,0 +1,48 @@
+from mcp_types import (
+    CallToolRequestParams,
+    CallToolResult,
+    ListToolsResult,
+    PaginatedRequestParams,
+    RequestParams,
+    TextContent,
+    Tool,
+)
+from pydantic import BaseModel
+
+from mcp.server import Server, ServerRequestContext
+
+SEARCH_BOOKS = Tool(
+    name="search_books",
+    description="Search the catalog by title or author.",
+    input_schema={
+        "type": "object",
+        "properties": {"query": {"type": "string"}, "limit": {"type": "integer"}},
+        "required": ["query", "limit"],
+    },
+)
+
+
+async def list_tools(ctx: ServerRequestContext, params: PaginatedRequestParams | None) -> ListToolsResult:
+    return ListToolsResult(tools=[SEARCH_BOOKS])
+
+
+async def call_tool(ctx: ServerRequestContext, params: CallToolRequestParams) -> CallToolResult:
+    args = params.arguments or {}
+    text = f"Found 3 books matching {args['query']!r} (showing up to {args['limit']})."
+    return CallToolResult(content=[TextContent(type="text", text=text)])
+
+
+class ReindexParams(RequestParams):
+    full: bool = False
+
+
+class ReindexResult(BaseModel):
+    indexed: int
+
+
+async def reindex(ctx: ServerRequestContext, params: ReindexParams) -> ReindexResult:
+    return ReindexResult(indexed=3)
+
+
+server = Server("Bookshop", on_list_tools=list_tools, on_call_tool=call_tool)
+server.add_request_handler("bookshop/reindex", ReindexParams, reindex)