Plan-and-Execute Pattern

What is the plan-and-execute pattern?

Faced with a complex task, some agents dive straight in and figure it out on the fly. Plan-and-execute hits the brakes first: the model writes a full plan up front, breaking the big goal into small steps, then works through that plan one step at a time.

Why plan first?

Fewer wasted turns
Complex tasks have moving parts. Sorting out the order up front avoids realizing halfway through that you're headed the wrong way and having to start over.
Cheaper and steadier
Splitting planning from execution means each step only has to focus on the current move. The model is less likely to drift or forget the goal.

How does it run?

Step one: plan
The model analyzes the task and outputs a checklist, maybe estimating which tool each step needs.
Step two: execute
Working down the list, it calls tools and collects results, stacking up the intermediate pieces.
Step three: assemble
Once all steps are done, it folds the results into a final answer for the user.

When does it shine?

Long tasks with many steps and dependencies — "research and write a report", "process a batch of data". For a one-step question, planning first is just overhead.

Bottom line: plan-and-execute is "make a list, then work it". A little planning time buys steadier, more accurate execution.