{
    "action": "tool_call",
    "reasoning": "I have evidence on industry distribution (63 industries), temporal patterns (34 months), and deal size distribution (69 distinct amounts). To determine natural segmentation, I should examine the valuation data since it's a key measure that hasn't been analyzed yet. Valuation often creates natural tiers (unicorn status, etc.) and combined with amount could reveal meaningful segments. I'll also check if there are patterns in lead investor concentration that might suggest investor-based segments.",
    "tool": "query_sql",
    "args": {
        "sql": "SELECT CASE WHEN Valuation = 'na' THEN 'Not disclosed' WHEN CAST(REPLACE(REPLACE(Valuation, '$', ''), ',', '') AS BIGINT) >= 1000000000 THEN 'Unicorn ($1B+)' WHEN CAST(REPLACE(REPLACE(Valuation, '$', ''), ',', '') AS BIGINT) >= 500000000 THEN 'High ($500M-$1B)' ELSE 'Emerging (<$500M)' END AS valuation_tier, COUNT(*) AS deal_count, SUM(CAST(REPLACE(REPLACE(Amount, '$', ''), ',', '') AS BIGINT)) AS total_funding, ROUND(AVG(CAST(REPLACE(REPLACE(Amount, '$', ''), ',', '') AS BIGINT)) / 1000000.0, 1) AS avg_deal_size_millions FROM raw.\"Largest US Venture Funding Deals Of 2023\" GROUP BY valuation_tier ORDER BY deal_count DESC",
        "purpose": "Segment deals by valuation tier to identify natural groupings based on company maturity/scale",
        "source": "raw"
    }
}