docs: cover the remaining Tier 1 audit items (#3325)

docs_src/lowlevel/tutorial007.py

@@ -0,0 +1,30 @@
+from mcp.server import Server, ServerRequestContext
+from mcp.types import CallToolRequestParams, CallToolResult, ListToolsResult, PaginatedRequestParams, TextContent, Tool
+
+FIND_BOOK = Tool(
+    name="find_book",
+    description="Find one book by ISBN, or by title and author.",
+    input_schema={
+        "type": "object",
+        "properties": {
+            "isbn": {"type": "string", "pattern": "^[0-9]{13}$"},
+            "title": {"type": "string"},
+            "author": {"type": "string"},
+        },
+        "oneOf": [{"required": ["isbn"]}, {"required": ["title", "author"]}],
+        "additionalProperties": False,
+    },
+)
+
+
+async def list_tools(ctx: ServerRequestContext, params: PaginatedRequestParams | None) -> ListToolsResult:
+    return ListToolsResult(tools=[FIND_BOOK])
+
+
+async def call_tool(ctx: ServerRequestContext, params: CallToolRequestParams) -> CallToolResult:
+    args = params.arguments or {}
+    found = f"ISBN {args['isbn']}" if "isbn" in args else f"{args['title']!r} by {args['author']}"
+    return CallToolResult(content=[TextContent(type="text", text=f"Found {found} on shelf C-3.")])
+
+
+server = Server("Bookshop", on_list_tools=list_tools, on_call_tool=call_tool)