Scenarios

A scenario describes one primary tool call, its deadline, and the expected observation.

{
  "name": "bounded delay succeeds",
  "call": { "tool": "delay", "args": { "delayMs": 250 } },
  "timeoutMs": 1000,
  "expect": {
    "outcome": "success",
    "maxDurationMs": 500,
    "result": { "isError": false, "textContains": "\"status\":\"delayed\"" }
  }
}

outcome is success, error, or timeout. textContains is case-sensitive and searches only MCP content items whose type is text. If timeoutMs is omitted, the CLI applies a 30-second deadline.

Observer verification

Use observe to make a separate call after the primary path. The calls are sequential and share the same MCP client connection.

{
  "name": "server remains responsive after a delay",
  "call": { "tool": "delay", "args": { "delayMs": 250 } },
  "timeoutMs": 1000,
  "expect": { "outcome": "success" },
  "observe": {
    "call": { "tool": "ping", "args": {} },
    "timeoutMs": 1000,
    "expect": {
      "outcome": "success",
      "result": { "isError": false, "textContains": "\"status\":\"ok\"" }
    }
  }
}

The observer runs even if the primary call errors or times out. An observer timeout, connection failure, or thrown error always fails verification.