What it's good at, and what it isn't

Strong areas

Drafting and rewriting text, summarising long documents, brainstorming options, explaining unfamiliar concepts, writing and reviewing code, and restructuring or reformatting existing information.

Weak areas

Precise facts, dates, and figures without a way to verify them. Legal citations and case law, which are a well-documented weak spot. Arithmetic on large or complex numbers, though many tools now use a calculator tool to compensate. Anything requiring genuine up-to-the-minute knowledge, unless the tool has live web access and actually uses it.

The general pattern: the more a task rewards fluent, well-organised language, the better these tools tend to be. The more a task depends on one specific fact being exactly right, the more you need to verify independently.