Tool return declarations require a `result` wrapper absent from `structuredContent` (Gmail and GitHub)

Problem

In Code Mode, the model-visible tool declarations describe CallToolResult<{ result: ... }>. Successful calls instead return the payload directly inside structuredContent.

This causes code following the declared return type to read undefined.

Reproduction

With the GitHub connector available, inspect the declaration for github_fetch_issue, then run this inside functions.exec:

const response = await tools.mcp__codex_apps__github_fetch_issue({
  repository_full_name: "openai/codex",
  issue_number: 35277
});
const data = response.structuredContent;

text({
  hasResult: Object.hasOwn(data, "result"),
  hasIssue: Object.hasOwn(data, "issue")
});

Observed:

{"hasResult": false, "hasIssue": true}

The declaration places issue under result. The same discrepancy reproduces with Gmail’s list_labels:

Both calls succeeded without a tool error.

Expected behavior

The model-visible return declaration should match the object delivered to JavaScript. Add regression coverage comparing the declared and delivered structures.

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 observations establish a declaration/runtime mismatch. They do not establish whether it originates in connector metadata, declaration generation, or result adaptation.

Start with the Code Mode tool declaration and the functions.exec reproductions for github_fetch_issue and gmail_list_labels. Compare each declared payload path with the delivered structuredContent object, then add regression coverage that verifies the declarations match both tool results.