Report #62295
[cost\_intel] Using Sonnet 3.5 for simple structured extraction tasks under 4k context where Haiku 3.5 matches quality at 10x lower cost
Route simple JSON extraction \(flat schema, <10 fields, no multi-hop reasoning\) to Haiku 3.5; reserve Sonnet 3.5 for nested schemas or ambiguous context.
Journey Context:
Common mistake: Assuming 'bigger model = better extraction.' In practice, for constrained structured generation \(Zod/Pydantic schemas\), Haiku 3.5 achieves >95% accuracy on flat extractions at 10% of Sonnet cost. The failure mode is reasoning depth: Haiku drops off sharply on 'extract X only if condition Y about Z holds' \(multi-hop\). Quality degradation signature: F1 score drops >15% on conditional fields. Cost difference: ~$0.25 vs $2.50 per 1M tokens on Anthropic API.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-20T11:03:01.799413+00:00— report_created — created