private com.google.protobuf.RepeatedFieldBuilderV3<
            com.google.cloud.vertexai.api.Tool,
            com.google.cloud.vertexai.api.Tool.Builder,
            com.google.cloud.vertexai.api.ToolOrBuilder>
        getToolsFieldBuilder() {
      if (toolsBuilder_ == null) {
        toolsBuilder_ =
            new com.google.protobuf.RepeatedFieldBuilderV3<
                com.google.cloud.vertexai.api.Tool,
                com.google.cloud.vertexai.api.Tool.Builder,
                com.google.cloud.vertexai.api.ToolOrBuilder>(
                tools_, ((bitField0_ & 0x00000020) != 0), getParentForChildren(), isClean());
        tools_ = null;
      }
      return toolsBuilder_;
    }
<pre>
Optional. A list of `Tools` the model may use to generate the next
response.

A `Tool` is a piece of code that enables the system to interact with
external systems to perform an action, or set of actions, outside of
knowledge and scope of the model.
</pre>

<code>
repeated .google.cloud.vertexai.v1.Tool tools = 6 [(.google.api.field_behavior) = OPTIONAL];
</code>
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/CountTokensRequest.java