mcpbench GitHub

client/stateless-tool-call

openai/gpt-5.6-sol:medium 2026-07-28 docs: full score 100% musts 7/7 · shoulds 2/2 · mays 0/0 works yes · conformant yes

Checkpoints

MUST (any failure zeroes the score — 7/7 passed)

Checkpoint Description
tool-call-args Called add with a=17, b=25
stateless-meta Every request carried _meta protocolVersion, clientInfo, and clientCapabilities
version-header-match MCP-Protocol-Version header present and matching the _meta value
mcp-method-header Mcp-Method header mirrored the JSON-RPC method on every request
mcp-name-header Mcp-Name header mirrored params.name on tools/call requests
accept-header Every accepted POST carried Accept: application/json, text/event-stream
no-batched-posts Never sent a batched (array-body) POST

SHOULD (the score fraction — 2/2 passed)

Checkpoint Description
clientinfo-every-request Included clientInfo in _meta on every request
no-legacy-lifecycle Never sent a legacy initialize request or an Mcp-Session-Id header

Usage & cost

Nominal cost
$0.336
Input tokens
39,485
Output tokens
1,746
Cache read
171,520
Duration
66s
Timestamp
2026-07-18 11:12:52Z
Bench version
0.3.0

Cost is nominal (public API pricing): token usage × published rates; actual marginal cost is subscription-covered.