mcp-context-cost

everything — context cost

1,708 tokens across 13 tools — light (1–5K). Measured 2026-09-30 under methodology v1.0.

An Anthropic request carries 1,082 of those tokens as tool definitions, and Claude counts those at 2,248.

   
server (self-reported) mcp-servers/everything v2.0.0
status measured
tokenizer tiktoken / o200k_base
launch command npx -y @modelcontextprotocol/server-everything
isolation docker · public.ecr.aws/docker/library/node:22-slim · network bridge · linux/amd64 · network enabled for package fetch; clean FS, no host credentials
env vars supplied none
canonical SHA-256 e61b2e1761ff2f931d030faf1dc192ca70247e52ff31d8633431b69ba6e00b7e
category official-reference
source https://github.com/modelcontextprotocol/servers

Where the tokens are

tool tokens share description input schema output schema
gzip-file-as-resource 247 14.5% 45 146 0
get-structured-content 195 11.4% 12 50 75
simulate-research-query 174 10.2% 49 72 0
get-annotated-message 147 8.6% 14 77 0
trigger-long-running-operation 128 7.5% 11 62 0
get-resource-reference 127 7.4% 11 62 0
get-resource-links 121 7.1% 12 55 0
get-sum 112 6.6% 6 53 0
echo 96 5.6% 6 40 0
toggle-simulated-logging 95 5.6% 14 24 0
toggle-subscriber-updates 90 5.3% 11 24 0
get-env 88 5.2% 11 24 0
get-tiny-image 86 5.0% 7 24 0

Each tool is tokenized on its own, so the parts do not sum exactly to the whole: the array adds its own brackets and commas, and the tokenizer merges tokens across object boundaries. The badge number is always the count of the whole array, never a sum of parts.

What this costs on Claude

Measured 2026-09-14 against claude-opus-5 via Anthropic’s count_tokens (method tools-delta/v1).

  tokens  
o200k, full capture 1,708 the badge number — every byte tools/list returned
o200k, Anthropic fields only 1,082 36.7% of the capture is MCP-only metadata
Claude, same fields 2,248 1.32× the badge number

An Anthropic tool definition carries name, description, and input_schema and nothing else, so title, annotations, outputSchema, execution, and icons are dropped before the request — that is the second row. The third row is the same tools counted by Anthropic, which is larger than the second because Anthropic’s tokenizer is denser on this content than o200k_base and the API adds its own framing (at most 328 tokens of it fixed, measured against a single minimal tool). The two effects run in opposite directions, which is why the Claude number is not a fixed multiple of the badge.

Over time

date tokens tools release measured in change
2026-08-16 1,708 13 not recorded not recorded —
2026-08-18 1,708 13 not recorded docker no change
2026-08-19 1,708 13 not recorded docker no change
2026-09-04 1,708 13 2.0.0 docker no change
2026-09-05 1,708 13 2.0.0 docker no change
2026-09-09 1,708 13 2.0.0 docker no change
2026-09-30 1,708 13 2.0.0 docker no change

Some of these sweeps predate the isolation column, so the conditions they were measured under are not on record.

Full series: results/history.csv.

Re-derive it

npx -y mcp-context-cost verify results/everything/measurement.json

That re-tokenizes the published capture and checks the count and the hash. If it disagrees with the badge, the badge is wrong — open an issue and it gets corrected.

Badge JSON · All servers · Leaderboard · Methodology