docs: add note for bigquery parameter replacement introduction. (#589)

For issue https://github.com/googleapis/genai-toolbox/issues/566

---------

Co-authored-by: Yuan <45984206+Yuan325@users.noreply.github.com>
Co-authored-by: Kurtis Van Gent <31518063+kurtisvg@users.noreply.github.com>

docs/en/resources/tools/bigquery-sql.md

@@ -20,6 +20,8 @@ parameters can be inserted into the query. BigQuery supports both named paramete
 (e.g., `@name`) and positional parameters (`?`), but they cannot be mixed in the
 same query.
 
+> **Note:** This tool uses [parameterized queries](https://cloud.google.com/bigquery/docs/parameterized-queries) to prevent SQL injections. Query parameters can be used as substitutes for arbitrary expressions. Parameters cannot be used as substitutes for identifiers, column names, table names, or other parts of the query.
+
 [bigquery-googlesql]: https://cloud.google.com/bigquery/docs/reference/standard-sql/
 
 ## Example

docs/en/samples/bigquery/colab_quickstart_bigquery.ipynb

@@ -493,7 +493,7 @@
         "from langgraph.checkpoint.memory import MemorySaver\n",
         "\n",
         "from toolbox_langchain import ToolboxClient\n",
-        "import pprint\n",
+        "\n",
         "prompt = \"\"\"\n",
         "  You're a helpful hotel assistant. You handle hotel searching, booking and\n",
         "  cancellations. When the user searches for a hotel, mention it's name, id,\n",