Design the plan-act-observe-decide loop for an agent tasked with the goal: 'Recommend a study strategy for a KAIST student preparing for the physics midterm in 2 weeks.' Write out what the agent should do at each phase: (1) what does it plan to do first? (2) what tool or action does it take? (3) what should it observe from the result? (4) what decision does it make—does it loop again, or synthesise and stop? Assume the agent has access to tools like web search, a calendar, and the ability to ask clarifying questions.