Codex found the shared attribution predicate recognising only tool calls,
text and signed thinking. A native image response often arrives with no
text and no tool call at all, so an image-only turn was read as producing
nothing: attribution stayed on whichever model spoke before it, and the
empty-stop rule could classify a successful generation as empty.
Everything the assistant can emit now counts except two: unsigned thinking,
which is not provider-authenticated and was already excluded, and
Anthropic's `fallback` marker, which records that a request was routed
elsewhere rather than carrying output. Redacted thinking and server-tool
blocks are real work by the same argument as the image.
The `toolUse` arm keeps its stricter rule — an orphaned toolUse stop needs
a tool_use block to anchor a later tool_result, and an image cannot.
Also switches the new test to the namespace import AGENTS.md requires for
node builtins.
enieuwy
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