In creative mode it is not possible to see the durability of the item unless you open the inventory

Thank you for your report!
However, this issue has been closed as Won't Fix.

If you'd like to post a suggestion or give further feedback, please visit the Minecraft Feedback Site or choose a link below.

Quick Links:
📓 Issue Guidelines – 💬 Community Support – 📧 Feedback – 📖 Game Wiki

Same issue as MCPE-13625