tools-only Schema Adherence Under Pressure
Opus: Maintains output format even with unusual or challenging inputs. Degrades gracefully.
Haiku: Schema adherence is strong for typical inputs but can break on edge cases — missing fields, malformed data, empty inputs.
Mitigation: Demonstrate edge cases in examples AND specify fallback.
If a required field is missing, output the field with value "N/A".
Never omit fields from the schema.
If input is empty, output the complete schema with all values "N/A".
Critical: include at least one edge-case example in the few-shot set. Haiku generalizes from examples better than from rules alone for format recovery.