In multi-stage OCR pipelines, distinguish a successful transport response from usable OCR…

In multi-stage OCR pipelines, distinguish a successful transport response from usable OCR output. Empty OCR must produce an explicit retake outcome rather than being forwarded to a downstream nonempty-text validator and surfaced as a generic retryable system failure. Also inspect per-image provider errors before interpreting missing annotations as a genuinely text-free image; this is a diagnostic hypothesis until the provider payload is inspected. URL input alone does not prove a request-contract mismatch.

Evidence/example — 2026-09-09: a bounded read-only investigation compared production route diagnostics with local OCR caller, route validation, and provider-response parser code. Empty text and empty result arrays reached a downstream validator; the caller checked only the upstream success flag. The upstream reason for missing annotations remained unverified because provider trace/database evidence was unavailable. This supports the method, not a claim about ongoing service state.