I have tested it with Eclipse Photon IDE but the issue is not appearing on our end. The list of all functions is displayed fine. Please upgrade your IDE to latest version and if you still face the problem then share your project with us and we will check it on our side. Also, you can visit API References for description of member functions and different classes.
We were able to observe the issue but we need to look into it more. We have logged the issue in our database for investigation and for a fix. Once, we will have some news for you, we will update you in this topic.
This issue has been logged as
CELLSJAVA-42693 - "Error retrieving proposal text" shown for Eclipse recommendations for functions after Maven import
We have investigated the issue and afraid to share that we cannot find the cause of such kind of issue. When using the jar in normal project(no maven), there is no problem. And we have tested our latest version 18.8 in maven project, we found 18.8 has no such kind of issue. You may please try it. For the issue of 18.7, we will make further investigation but not sure we can find the solution.