What must be included in a macro definition to ensure functionality?

In a macro definition, including at least one parameter is essential for ensuring functionality because parameters allow the macro to accept dynamic inputs when it is called. This flexibility enables users to tailor the macro's behavior based on varying contexts, such as specifying different fields, search criteria, or other dynamic values. By defining a parameter, the macro becomes more versatile and applicable to a wider range of scenarios, making it a powerful tool for enhancing search efficiency and consistency within Splunk.

Other options do not align with the concept of effective macro definition. Defining a macro without parameters would limit its usability, as it would not be able to adjust to different inputs. Specifying complex commands solely in a macro is not a requirement; macros can encapsulate simpler commands as well. Additionally, while time ranges are important in many searches, they are not inherently required for the functionality of a macro itself.