Add Agent Toolbelt to Commercial & Proprietary Services (#425)

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

README.md

@@ -636,6 +636,7 @@ A curated list of insanely awesome libraries, packages and resources for Quants
 - [ValueRay](https://www.valueray.com/api) - Technical, quantitative and sentiment data for stocks and ETFs with risk metrics, peer percentiles and market regime signals. Optimized for AI/LLM agents.
 - [VertData](https://vertdata.com) - Institutional-grade financial intelligence platform. Track 43K+ congressional trades (STOCK Act), SEC insider Form 4 filings, 25 superinvestor 13F portfolios, CFTC futures positioning, ARK ETF holdings, and short interest — all scored by AI for signal strength.
 - [KeepRule](https://keeprule.com/) - Curated library of decision-making principles and investment wisdom from masters like Buffett and Munger, featuring mental models for better investment thinking.
+- [Agent Toolbelt](https://www.agenttoolbelt.live) - AI stock-research API returning structured analysis (investment thesis, valuation verdict, insider-signal read, earnings, bull-vs-bear, moat, watchlist ranking) for US equities from Polygon/Finnhub/FMP data. Optimized for LLM agents; free tier.
 - [ML-Quant](https://www.ml-quant.com/) - Top Quant resources like ArXiv (sanity), SSRN, RePec, Journals, Podcasts, Videos, and Blogs.
 - [RealMarketAPI](https://realmarketapi.com/) - Provides ultra-low latency market data for gold, forex, crypto, and stocks via REST, WebSocket, and MCP—built for speed, reliability, and scale.
 - [The Stock Radar](https://thestockradar.com) - Daily multi-language stock movers, technical analysis, earnings recaps, and weekly research reports across 6 markets (US, Korea, Japan, Taiwan, India, Germany) published in 6 languages.