DSH Llm Kiro

Key features

• Kiro has no system slot, so the harness system prompt is prepended to the earliest user turn, where thinking markers also go.
• The response is a vnd.amazon.eventstream frame sequence.
• History is folded into the strict user/assistant alternation the service requires
• Tool schemas ride on the current turn.
• A tool result whose issuing call is absent from history (compaction dropped it) is carried as text, because the service rejects the unmatched id.