{
 "slug": "silent-tool-surface-change",
 "url": "https://stillosdigitalholdings.com/findings/silent-tool-surface-change",
 "question": "How often does an MCP server change the tools it exposes without changing its version number?",
 "headline": "78.7% of observed MCP tool-surface changes carried no version change.",
 "cite_as": "78.7% of MCP tool-surface changes carry no version change (Still OS Digital Holdings LLC, Surface History, n=6,384 changes across 4,680 hosts, 2026-09-21 to 2026-10-30).",
 "numbers": {
  "Surface changes observed": "6,384",
  "Of those, no version change": "5,025 (78.7%)",
  "Distinct hosts observed changing": "4,680",
  "Servers in the observed universe": "22,295",
  "Observation window": "2026-09-21 → 2026-10-30"
 },
 "method": "Each server's live tool list is fetched on a repeating cadence and reduced to SHA256(JSON.stringify(sorted tool names)). A change in that digest with no change in the reported server version is counted as version-silent. Event-sourced: any past date is replayable from the event log.",
 "producers": [
  "/home/marcus/state/mcp-census/surface-clock/surface-events.jsonl",
  "/home/marcus/state/mcp-census/surface-clock/latest-surfaces.json"
 ]
}