How to reproduce:
1. Create a new Unity project
2. Create a new script
3. Add "using UnityEngine.Tilemaps" to the top
4. Create a new object of type ITilemap
5. Try to call any method from created object

Expected results: All of the methods have proper descriptions
Actual results: Many method descriptions are cut off in the middle of a sentence

Reproducible with: 2017.2.3p3, 2017.4.9f1, 2018.1.9f1, 2018.2.3f1, 2018.3.0a7
Tilemap feature was introduced in 2017.2