low effort → 1 diff pass → no verify → ≤8 findings
One tool call: read the unified diff (git diff @{upstream}...HEAD; git diff HEAD
to cover both committed and uncommitted changes, or git diff main...HEAD /
the target passed as an argument). No subagents, no full-file reads.
Flag runtime-correctness bugs visible from the hunk alone: inverted/wrong
condition, off-by-one, null/undefined deref where adjacent lines show the value
can be absent, removed guard, falsy-zero check, missing await,
wrong-variable copy-paste, error swallowed in a catch that should propagate.
Also flag — still from the hunk alone — new code that duplicates an existing
helper visible in the diff context, and dead code the diff leaves behind.
Do not flag style, naming, perf, missing tests, or anything outside the hunk.
Output at most 8 findings, most-severe first, one line each:
path/to/file.ext:123 — what's wrong and the concrete failure.
Target at least min(files_changed, 4) findings — if you see fewer, widen to other hunks in the same diff before stopping. If fewer than 4 genuine findings exist, emit what you have.