Report structural complexity of a source file, function by function. FREE.
Measures per-function length, max nesting depth, and a cyclomatic-style
branch count (if/for/while/case/&&/||/except), flagging functions too
long or too deeply nested to review confidently. Typical input
{"code": "<file contents>"} returns {"functions": N, "detail":
[{"name": ..., "start": N, "lines": N, "branches": N, "max_depth": N}],
"flags": ["..."], "note": "..."}.
Use when structure rather than correctness is the question. Not for
vulnerabilities (security_deep_dive). Errors: on invalid, missing, or malformed input this tool never raises a protocol error — it returns {"error": "<what is wrong and how to fix it>"}. Every call is read-only and idempotent, so after correcting the input it is always safe to retry.