Simplicity is the first principle

Human readability comes first; coding-agent traceability is the minimum gate. A human should understand the code in one pass. An agent must at least be able to trace a feature from CLI flag to executed branch, tensor/record, metric, and test without reconstructing hidden control flow. Every rule below is an instance of that ordering. These are hard correctness rules, not style preferences. A violation is a bug and must be fixed before the change ships.

1. Code a human can't follow at a glance is a bug. If a reviewer can't read a function top-to-bottom in one pass, restructure or delete it. Nesting, indirection, and clever constructs count against correctness — cleverness that costs comprehension is a defect, whatever it saves.

2. Too much / redundant code is a bug. Solve the problem in the fewest lines that stay readable. Prefer deleting code over adding it. A fix that adds more than ~20 lines for a problem statable in one sentence is suspect — find the smaller fix first.