It would be nice to give more clear documentation of each plugin
That’s the responsibility of each individual plugin to provide.
The plugin central is mainly a listing, repository, and search for the plugins.
Each plugin on publication can define the description and a link.
The link usually links to the project page where you then have proper documentation, source, issue tracker, and so on.
That this specific plugin you linked to has a not-so-helpful link on the plugin page is to be reported to that plugin. Then they can improve on that if they want to.
It also say in which repository these plugin should be searched what if a plugin is in google() rather than mavenCentral() etc
All plugins that are listed on the plugin portal are available in gradlePluginPortal() repository, otherwise they were not listed. Besides that each page there contains exactly that informationk, just with explicit URL, in the legacy application part.