mcp-context-cost

slack-legacy — context cost

681 tokens across 8 tools — lean (< 1K). Measured 2026-08-16 under methodology v1.0.

   
server (self-reported) Slack MCP Server v1.0.0
status measured
tokenizer tiktoken / o200k_base
launch command npx -y @modelcontextprotocol/server-slack
isolation docker · public.ecr.aws/docker/library/node:22-slim · network bridge · network enabled for package fetch; clean FS, no host credentials
env vars supplied SLACK_BOT_TOKEN, SLACK_TEAM_ID
canonical SHA-256 5939f969618ff709e86ff0599b80cc8f418db8904b4304a6eeb82a25f30ccd81
category official-reference
source https://github.com/modelcontextprotocol/servers-archived

Where the tokens are

tool tokens share description schema
slack_reply_to_thread 124 18.2% 8 102
slack_get_thread_replies 110 16.2% 7 88
slack_add_reaction 95 14.0% 7 74
slack_get_users 80 11.7% 14 53
slack_list_channels 76 11.2% 11 52
slack_get_channel_history 73 10.7% 6 53
slack_post_message 70 10.3% 8 49
slack_get_user_profile 51 7.5% 8 29

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.

Re-derive it

npx -y mcp-context-cost verify results/slack-legacy/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