ArcGIS Pro 2.9.5
As discussed with @JonathanNeal in a separate message, I'm wondering if it would help to add a selection icon in GP tool descriptions in the Catalog Pane to indicate if the tool honors selections.
For example, with the Join Field tool, if rows are selected in the join table via Select By Attributes, only those selected rows will be populated in the new fields in the Input table. Related use case:
https://community.esri.com/t5/data-management-questions/1-m-join-to-pull-feature-with-specific-attri...
However, the Add Join tool does not work that way; selection are not honored.
I'm aware that it's generally known that most geoprocessing tools honor selections unless otherwise specified. But there are exceptions, so I think it would be helpful to clarify this important difference between similar tools.