What does the descriptor liferay-portlet.xml define?

The descriptor liferay-portlet.xml is a critical configuration file within Liferay that defines various settings and properties for portlet applications. It primarily focuses on Liferay-specific features that enhance the functionality and integration of portlets within the Liferay platform. This includes configuration options like the portlet's display name, description, security settings, and various lifecycle behaviors that are unique to Liferay.

While it is true that the file may indirectly influence elements such as the Add Application menu or may interact with aspects that determine portlets intended to run specifically on Liferay, the core focus of liferay-portlet.xml is to define and declare Liferay-specific portlet features and configurations. Hence, the most accurate choice reflects the primary purpose of this descriptor.