Every attribute defined for Asset Lifecycle Information Management should have an IsSearchable attribute as part of its entity metadata. There are certain intrinsic properties that will have IsSearchable set to "True". Other properties that are not intended to be searchable will be set to "False". The Entity Metadata tool simplifies the process of editing intrinsic properties.

You can use the Entity Metadata Helper to view and edit the IsSearchable attribute. See Entity Metadata Helper Tool for more information.