You are designing an AI agent for summarizing medical documents that include images and text...

The selected option specifically D states “Multi-modal model integration to handle both text and vision inputs”, which matches the operational requirement rather than a superficial wording match. The best answer is Option D when the design is judged by reliability, latency budget, auditability, and maintainability rather than demo simplicity. Operationally, the design depends on tool contracts that can be versioned, tested, and observed independently from the reasoning loop. Medical images and text require a model path that can encode vision and language. Guardrails and retries improve safety and reliability, but they do not create multimodal perception. That is why the other options are traps: manual tool wiring scales poorly as the catalog grows and usually fails silently when a vendor updates parameters or response fields. The stack-level anchor is clear: NeMo Agent Toolkit treats agents, tools, and workflows as composable functions, so tool-calling agents can choose from names, descriptions, and schemas rather than guessed endpoints. It also creates clean evidence for audits, incident review, and root-cause analysis when behavior drifts.