LLM task planner prompt builder
LLMs handle multi-step tasks far better when they plan before they act — otherwise they commit to an approach mid-stream and you only discover the flaw after they have produced output. This builder prepends a structured planning phase to your task: identify sub-tasks, order them by dependency, optionally estimate effort and flag blockers, and present the plan for review before execution begins.
Why planning prompts improve multi-step tasks
When a model jumps straight into a complex task, two problems arise. First, it chooses an approach without surfacing alternatives — you only discover it picked the wrong one after reading several paragraphs of output. Second, it starts steps that depend on earlier unfinished steps, producing incoherent or contradictory output halfway through.
A planning phase addresses both: the model declares its intended approach before starting, so you can redirect if it has misread the task; and it sequences sub-tasks explicitly, so later steps have a declared dependency on earlier ones. The plan is also reusable — run the same task again and you can paste the plan back in to skip the planning phase and go straight to execution.
Planning depth levels
Light — the model lists three to five high-level steps in the order it will tackle them. Low overhead, good for moderately complex tasks where the general approach is obvious.
Standard — the model decomposes into sub-tasks, sequences them by dependency, and flags any step where it needs a clarification or where multiple approaches exist. Good default for most multi-step tasks.
Deep — the model adds estimated effort per step, identifies the riskiest step and proposes an alternative, and lists any external dependencies or blockers. Adds overhead but catches the most problems before execution begins. Best for long-horizon tasks, agent loops, and tasks with irreversible steps.
How it works
You paste the task, pick a planning depth, and choose whether the plan comes back as a numbered list or a JSON array. The tool assembles a prompt that instructs the model to decompose the task, sequence sub-tasks by dependency, and — at deeper levels — estimate effort, flag risks, and suggest an alternative for the riskiest step. It then tells the model to pause for confirmation before executing. JSON output is structured for agent loops; the numbered list suits human review. The prompt is built in your browser.
Tips and notes
- Review the plan, not just the result. The whole point is to catch a bad approach early — read the plan before letting the model run.
- Match depth to complexity. Deep mode shines on hard tasks but adds noise to trivial ones.
- Use JSON for agents. If a program executes each step, JSON output gives you ids and dependencies to drive the loop.
- Clarify first. Pair with an ambiguity-resolver block so the model resolves vagueness before planning around it.
- If the plan itself looks wrong, stop. The planning phase only helps if you actually read the plan and redirect before execution — skipping that review negates the benefit.