The capitalisation of tooltips on question pages is quite inconsistent.
Looking, for instance, at the featured Meta Stack Overflow question "Take the 2019 Developer Survey", many inconsistencies can be seen in tooltip capitalisation in the UI:
1. Places that have tooltips that start with uppercase characters:
2. Places that have tooltips that start with lowercase characters:
3. A place that has a mix of tooltips that start with and lowercase and uppercase characters:
Even if the justification for the lowercase tooltips for the share/edit/close/flag links start with lowercase characters is that the links themselves are in lowercase, the answer sort order links are also in lowercase but the tooltips are in uppercase.
Could this be changed? It seems quite... inconsistent.
I've had a look in the User Experience Stack Exchange and couldn't find any questions which relate specifically to tooltip capitalisation, but I imagine that any such question would specify that the system be consistent.