JSR 250 ("Common Annotations 1.0") specified a set of common annotations for application development. Some of them were included in Java SE 6 and later, but many of them are Java EE-specific and were added in Java EE 5. Tomcat 6 included these annotations since Tomcat supported some of them. The annotations included in Tomcat 6 are:

javax.annotation.Generated
javax.annotation.PostConstruct
javax.annotation.PreDestroy
javax.annotation.Resource
javax.annotation.Resources
javax.annotation.security.DeclareRoles
javax.annotation.security.DenyAll
javax.annotation.security.PermitAll
javax.annotation.security.RolesAllowed
javax.annotation.security.RunAs

This was fine in Java EE 5 / Tomcat 6. However, Java EE 6 ("Common Annotations 1.1") added the following annotations that Tomcat 7 never included:

javax.annotation.ManagedBean
javax.annotation.sql.DataSourceDefinition
javax.annotation.sql.DataSourceDefinitions

Furthermore, Java EE 7 ("Common Annotations 1.2") added the following annotation that Tomcat 8 has not yet included:

javax.annotation.Priority

Tomcat should included these annotations in its "annotations-api.jar". Other frameworks (like Spring Framework and JPA providers) make use of these new annotations. Since Tomcat does not include them, the /correct/ thing for an application that needs them to do is include the official javax.annotation-api.jar artifact in their application. However, this JAR redefines annotations already supplied by Tomcat, which could lead to hard-to-diagnose errors (similar to why an application should never include the servlet-api artifact in their application). Adding these missing annotations would remove the requirement for applications to include the problem JAR in their application.

Tomcat 7 should ship @ManagedBean, @DataSourceDefinition, and @DataSourceDefinitions. Tomcat 8 should ship with @Priority.