Gmail `search_emails` returns `from_` although its return declaration requires `from`

Problem

The model-visible declaration for Gmail search_emails requires emails[].from: string. Returned email records instead contain from_, with from absent.

This remains observable after accommodating the separate result wrapper discrepancy.

Reproduction

Connect Gmail and use a query that matches at least one message. Run inside functions.exec:

const response = await tools.mcp__codex_apps__gmail_search_emails({
  query: "subject:newsletter -in:spam -in:trash",
  max_results: 1
});
const data = response.structuredContent;
const payload = data.result ?? data;
const email = payload.emails[0];
if (!email) throw new Error("Choose a query matching one message.");

text({
  hasFrom: Object.hasOwn(email, "from"),
  hasFromUnderscore: Object.hasOwn(email, "from_"),
  fromUnderscoreType: typeof email.from_
});

Observed:

{
  "hasFrom": false,
  "hasFromUnderscore": true,
  "fromUnderscoreType": "string"
}

The call succeeded. Code using the declared email.from receives undefined.

Expected behavior

The advertised sender field and serialized response should agree. Add regression coverage for the field name in a nonempty search result.

Environment and scope

Reproduced September 6, 2026 through functions.exec, on macOS 26.6.2. Locally installed CLI: 0.153.4; Gmail plugin manifest: 0.1.10.

The reproduction reports only field presence and types. It includes no message content or account identifiers.

Start at the Gmail search_emails entry point exercised through functions.exec and trace its declared response shape alongside the serialized email records. Add regression coverage for a nonempty search result that checks the advertised sender field and response field name agree; the test should pass without relying on message content or account identifiers.