Decompose a task without multiplying mistakes

Learning outcome: Put checks between dependent stages.

Breaking work into steps helps when each step has an inspectable output. Extraction, calculation and drafting can be reviewed separately. The danger is allowing an early error to become an unquestioned input to every later step.

Give each stage a small contract: required inputs, permitted transformations and a check before handover. Preserve source references through the chain. If a figure is unresolved, pass that uncertainty along instead of silently filling it. Avoid splitting a simple task into many model calls merely because a longer chain looks sophisticated. Every extra stage adds another point where information can be lost.

Worked example

A fictional supplier comparison has three stages. Extract the quoted charges with their units; calculate comparable totals; draft a recommendation. If monthly support is extracted as an annual charge, the final recommendation can be fluent and still wrong. Checking units before calculation prevents the drafting stage from concealing the original mistake.

Try it yourself

Draw a three-stage process for comparing two quotes. At each boundary write one check and describe what happens when it fails.

You can do this exercise on paper. If using an assistant, keep to the fictional material and an approved tool.

Check your understanding

Where should a monthly-versus-annual unit error be checked?

1. Before the extracted value enters the calculation
2. Only after the recommendation is published
3. Only if the final total looks surprising

Workbook

Download the course workbook to record your answer and compare it after the knowledge check.

Further reading

• Anthropic: context engineering
• Anthropic: tools for agents