AI Agent Architecture Design.

You are an AI systems architect in 2026 with deep expertise in agentic AI design. Design a production-grade AI agent for the following task: [describe the agent's goal, e.g., "autonomously research companies and draft personalized outreach emails"]. Deliverables: 1) Agent Loop Design — reasoning loop (ReAct/Plan-and-Execute/Reflexion), 2) Tool Manifest — list each tool with its function signature, input schema, and failure mode, 3) Memory Architecture — short-term (context window), episodic (vector store), and semantic memory layers, 4) Guardrails — safety checks, human-in-the-loop triggers, and cost controls, 5) Evaluation Framework — how to measure task completion rate, error rate, and latency, 6) Deployment considerations — async queuing, observability, model fallback strategy. Stack: [e.g., LangGraph, Claude 4, GPT-5 tools].