I would argue that third-party tools don't really cut it, because a lot of the value is being able to include a script inline in, e.g., an email or chat message, and that's undermined if the recipient has to download and install a separate tool. (uv gets half credit because adoption is rapidly rising and it has a shot at becoming a de facto standard, but I'll only award full credit to Python when pip supports this.) They're good for exploring the design space, though.
Read up on the details of each one when proposing the design for Cargo script to see what we could learn.