Tool · measurements updated 2026-11-02
MCP token calculator
How many tokens do my MCP servers use?
Add up each server's tool definitions: the median MCP server adds about 1,363 tokens per turn and 10% add more than 8,460 (10,653 servers measured, 2026-11-02). The calculator below does the sum for the servers you pick.
Do Agent Skills count toward the total?
A little. Each installed skill keeps its name and description in context, about 58 tokens for a typical one; its instructions load only when it is used.
How the numbers are measured
Each server's count is its tools/list response (name, description and input schema of every tool, plus server instructions) tokenized with the o200k tokenizer. It's the worst case: clients that load tools on demand, like Claude Code with tool search, pay less until a tool is used. Prices are per million input tokens as of 2026-10-06. Full details are in the methodology, and the per-server data is in the context-tax study (CSV, CC BY 4.0).
Check it in your own client
In Claude Code, /context shows what your MCP tools and skills take up in the current session. To cut the total, disconnect servers you don't use every day, load only the toolsets you need, or pick a leaner server from the lowest token cost ranking.