HISTOR snapshot 2026-10-26: MCP tool definitions and how they change

HISTOR reads the tool list (tools/list) of every remote MCP server in the official MCP registry on a polling schedule, and of npm/PyPI MCP packages run in a sandbox once per published version (new versions first, a few hundred a day). It records the exact tool definitions, pins them by digest, and writes a signed label to a public RFC 9162 Merkle log whenever a tool set first appears, stays the same, or changes. This snapshot is that record as files. 85,913 listed servers (34,171 remote endpoints, 51,742 packages), plus 3,364 delisted 40,738 with a recorded tool set; 11,528 changed at least once 31,660 recorded changes, 2026-09-24 to 2026-10-26 66,649 distinct tool sets (current ones and every one a change replaced) 752 servers with a block-tier WARDEN pattern match, 15,273 advise-only One file is new since the 2026-10-25 version: package_observations.jsonl.gz. README.md describes every file; manifest.json holds the full hashes and counts, signed by the log's key. Live view and per-server pages: https://histor.modelmarket.dev · code: https://github.com/alexar76/histor License and rights The compilation, digests, labels, scans and verdicts are CC-BY-4.0: cite "HISTOR, https://histor.modelmarket.dev, snapshot 2026-10-26". Tool names, descriptions and schemas are reproduced as each server published them; their rights stay with their authors. They are included so the definitions can be studied and checked. A server operator who wants out: open an issue on https://github.com/alexar76/histor with the endpoint or host. Opted-out servers are left out of every later snapshot.