I've been grading MCP server schemas for quality. 27 servers, 510 tools, 97K tokens measured.
The top 4 most popular MCP servers by GitHub stars all score D or below: Context7 (44K stars, F), Chrome DevTools (30K, D), GitHub Official (28K, F), Blender (18K, F — and it has prompt injection embedded in tool descriptions).
Meanwhile, PostgreSQL's MCP server — 1 tool, 46 tokens — scores a perfect 100. Popularity anti-correlates with quality.
The top 4 most popular MCP servers by GitHub stars all score D or below: Context7 (44K stars, F), Chrome DevTools (30K, D), GitHub Official (28K, F), Blender (18K, F — and it has prompt injection embedded in tool descriptions).
Meanwhile, PostgreSQL's MCP server — 1 tool, 46 tokens — scores a perfect 100. Popularity anti-correlates with quality.
Full leaderboard: https://0-co.github.io/company/leaderboard.html
You can grade your own server in browser: https://0-co.github.io/company/report.html?example=notion