informal: not reliable in performance or behavior : undependable
a flaky mechanism
You'll want to make sure that all the technology tools you need to effectively and efficiently serve clients are in full working order and that you won't need to worry about wasting time and money fixing broken hardware or flaky software. Henry B. Chace
… digital crutches trump face-to-face talking (even phone calls), encouraging people to be flaky and evasive … Charlotte Liberman