a16z's Yoko Li on agent loops and what it takes for them to work: "The first loops that worked well were coding loops. This is not an accident. Code is both editable and executable. An agent can change one function, run the program, read the test failure, and try again." Loops sit on two axes: how editable the artifact is, and how verifiable the result is. "Code often sits in the upper-right corner. It is easy to edit, and it has relatively strong verifiers." "Open-ended image generation…