fix notebook explanation

cookbook/Prompt_Caching_with_Anthropic.ipynb

@@ -12,7 +12,7 @@
         "  <img src=\"https://colab.research.google.com/assets/colab-badge.svg\" alt=\"Open In Colab\"/>\n",
         "</a>\n",
         "\n",
-        "Prompt caching allows you to store and reuse context within your prompt saving time and money. When using the prompt cache feature from Anthropic, the chat messages have to be expressed in blocks rather than simple text, so that for each block you can define the cache behaviour.\n",
+        "Prompt caching allows you to store and reuse context within your prompt saving time and money. When using the prompt cache feature from Anthropic, the chat messages have to be expressed in blocks rather than simple text, so that you can designate one of the for being cached.\n",
         "\n",
         "Let's see how Banks makes this super easy."
       ]
@@ -75,7 +75,7 @@
       "source": [
         "With Banks we can define which part of the prompt specifically will be cached. \n",
         "Directly from the prompt template text, we can use the `cache_control` built-in filter to tell Anthropic that\n",
-        "we want to cache the whole text resulting from the `{{ book }}` template block."
+        "we want to cache the prompt up to and including the `{{ book }}` template block."
       ]
     },
     {
@@ -98,9 +98,11 @@
         "{% chat role=\"user\" %}\n",
         "Analyze this book:\n",
         "\n",
-        "{# Only this part of the message content (the book content) will be cached #}\n",
+        "{# Only this part of the message content (including the book content) will be cached #}\n",
         "{{ book | cache_control(\"ephemeral\") }}\n",
         "\n",
+        "{# This part won't be cached instead #}\n",
+        "\n",
         "What is the title of this book? Only output the title.\n",
         "{% endchat %}\n",
         "\"\"\"\n",