@mcp.tool()
def summarize_run(run_dir: str) -> dict:
    """Audit a run from its CSV reports. Returns counts only — never text or tag values."""
    run = Path(run_dir).expanduser().resolve()
    pixels = _read_csv_rows(run / "aegis_pixel_detections.csv")
    tags = _read_csv_rows(run / "aegis_tag_actions.csv")
    return {
        "pixel_decisions": Counter(r["decision"] for r in pixels),  # redacted / safelisted / low_confidence
        "tag_actions": Counter(r["action"] for r in tags),          # REMOVE / REMAP / ZERO / DUMMY / ATTEST