Codify MCP tool name requirements and add title

index.bs

@@ -118,6 +118,14 @@ A <dfn>tool definition</dfn> is a [=struct=] with the following [=struct/items=]
   :: a [=string=] uniquely identifying a tool registered within a [=model context=]'s [=model
      context/tool map=]; it is the same as the [=map/key=] identifying this object.
 
+     The [=tool definition/name=] SHOULD:
+     * Be between 1 and 128 characters in length (inclusive).
+     * Be considered case-sensitive.
+     * Only consist of uppercase and lowercase ASCII letters (A-Z, a-z), digits (0-9), underscore (_), hyphen (-), and dot (.).
+
+  : <dfn>title</dfn>
+  :: A [=string=] representing a human-readable title of the tool to be used in the user interface to represent the tool.
+
   : <dfn>description</dfn>
   :: a [=string=].