FYI: tool-schema context cost went 5,462 → 6,928 tokens (+27%) between 2026-08-19 and 2026-09-03

Not a bug report — a measurement you may want to know about.

blender-mcp is one of 106 MCP servers measured on a rotation by mcp-context-cost (credential-free Docker, tools/list captured twice, o200k_base over the canonical bytes, with the raw capture, its SHA-256 and the exact launch command published behind every number). Between the sweeps of 2026-08-19 and 2026-09-03 its cost went 5,462 → 6,928 tokens (+1,466, +26.8%) as the tool count went 25 → 28, and it has held there through 2026-09-04.

That is what every request carries in a client that loads tool definitions up front (Claude Desktop, Cursor, VS Code, Windsurf). Claude Code defers definitions by default and pays only tool names plus instructions at session start, which is measured separately on the page.

• The page, with the per-tool breakdown and the history line: https://athakur3.github.io/mcp-context-cost/servers/blender.html
• The movement report: https://github.com/athakur3/mcp-context-cost/blob/main/results/regressions.md
• Method: https://github.com/athakur3/mcp-context-cost/blob/main/docs/METHODOLOGY.md

I can't say which tools account for the increase: per-tool captures only start from 2026-09-04, so for this movement only the totals and the tool count are on record.

If it's useful, a five-line GitHub Action runs the same measurement on every PR and fails one that adds more than a threshold you set, with the per-tool diff. Happy to open that as a PR, or to close this if it isn't wanted. Disclosure: I maintain mcp-context-cost.