Currently the question on Confirm Merge looks like
"Are you sure you want to merge into your current branch?"

But this is not informative enough and can lead to unwanted merges

It would be nice to have it like this:
"Are you sure you want to merge [%source_branch%] into [%current_branch%]?"

Example:
"Are you sure you want to merge master into feature/XYZ-123?"

Or one hint as second line:
"Are you sure you want to merge into your current branch?
[%source_branch%] → [%current_branch%]"

Example:
"Are you sure you want to merge into your current branch?
master → feature/XYZ-123"