mcp-context-cost

github — context cost

54,422 tokens across 44 tools — very heavy (≥ 30K). Measured 2026-08-16 under methodology v1.0.

   
server (self-reported) github-mcp-server v1.9.0
status measured
tokenizer tiktoken / o200k_base
launch command docker run -i --rm -e GITHUB_PERSONAL_ACCESS_TOKEN=dummy ghcr.io/github/github-mcp-server
isolation docker · command is itself a docker run (host-spawned container)
env vars supplied GITHUB_PERSONAL_ACCESS_TOKEN
canonical SHA-256 086879383bcdc68ea1b960a141ab1b41cb2a203321c4440553c033b5e9a5344d
category vendor-official
source https://github.com/github/github-mcp-server

Where the tokens are

tool tokens share description schema
issue_write 1,890 3.5% 14 619
list_issues 1,783 3.3% 33 497
pull_request_read 1,737 3.2% 12 515
pull_request_review_write 1,681 3.1% 242 213
search_issues 1,678 3.1% 34 390
sub_issue_write 1,617 3.0% 15 347
search_pull_requests 1,595 2.9% 18 370
issue_read 1,575 2.9% 12 310
list_pull_requests 1,569 2.9% 31 332
search_users 1,566 2.9% 26 158
assign_copilot_to_issue 1,549 2.8% 62 150
add_comment_to_pending_review 1,534 2.8% 32 284
add_issue_comment 1,513 2.8% 65 190
add_reply_to_pull_request_comment 1,454 2.7% 51 191
request_copilot_review 1,426 2.6% 29 69
update_pull_request 1,419 2.6% 11 202
list_issue_fields 1,394 2.6% 49 91
create_pull_request 1,391 2.6% 11 173
list_issue_types 1,359 2.5% 24 80
get_label 1,337 2.5% 8 72
update_pull_request_branch 1,315 2.4% 16 91
merge_pull_request 1,259 2.3% 10 124
fork_repository 1,242 2.3% 11 66
get_team_members 1,117 2.1% 18 47
get_teams 1,102 2.0% 19 32
get_me 1,096 2.0% 35 9
list_commits 1,092 2.0% 41 345
search_code 1,075 2.0% 33 338
search_commits 1,069 2.0% 37 327
create_or_update_file 987 1.8% 94 177

14 smaller tools omitted (11,999 tokens combined) — all of them are in the raw capture.

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 2026-08-16 against claude-opus-5 via Anthropic’s count_tokens (method tools-delta/v1).

  tokens  
o200k, full capture 54,422 the badge number — every byte tools/list returned
o200k, Anthropic fields only 10,535 80.6% of the capture is MCP-only metadata
Claude, same fields 18,406 0.34× 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.

Re-derive it

npx -y mcp-context-cost verify results/github/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