Methodology

• Catalog: every server in the official MCP registry, re-crawled daily (all versions; the latest version defines the canonical record).
• Reachability: for servers with remote (HTTP) endpoints we perform a standard MCP handshake (initialize + tools/list) daily and record the outcome: reachable, auth required, unreachable, or protocol error, plus latency and the protocol version the server reports.
• Tool-definition integrity: when a server hands us its tool list, we compute a SHA-256 hash of each tool's canonical JSON and of the sorted set. When a hash changes between probes, we record exactly which tools were added, removed, or changed, and which fields differed. These are the “tools changed” events you see on server pages.
  We hash the fields the MCP specification defines for a tool: name, title, description, inputSchema, outputSchema, annotations, icons, execution and _meta. Non-standard vendor fields (for example a private build identifier that changes on every deploy) are excluded, so the hash tracks what a tool claims to do rather than incidental churn.
• Repository vitality: for servers that link a GitHub repository, the date of last push, star count, archived flag, and fork flag. Refreshed on a rolling basis.

• Probes are read-only: we never invoke a server's tools, never send credentials, and never execute anything a server returns.
• We only probe remote HTTP endpoints listed in the public registry. We do not run stdio server packages.
• Probes are rate-limited and identified by a User-Agent with a contact address. Server operators can reach us any time at corey@macroalchemy.com.

A green badge means the server responded to a standard handshake, not that it is safe, well-designed, or trustworthy. A “tools changed” event means the definitions differ; many changes are perfectly legitimate releases. Toolpin gives you the facts and the diff. The judgment stays with you.

If a fact on this site is wrong (a misattributed repository, a stale status, a mis-linked endpoint), email corey@macroalchemy.com and we will investigate and correct it promptly.