Overly Vague Instructions

The most common beginner prompt mistake is vagueness: writing instructions so general that the model cannot reliably produce what you actually want.

"Write something good about AI."

This prompt contains no information about format, audience, length, tone, angle, or purpose. The model will produce something — but the chance that it matches what you had in mind is low. Vague prompts produce inconsistent, hard-to-predict outputs that require heavy editing.

A prompt is vague when it is missing one or more of the dimensions the model needs to make a good decision. The key dimensions:

• What — the specific topic or task
• Who — the target audience
• Why — the purpose or goal
• How — the format, structure, and style
• How much — the length or scope

You do not always need all five, but the more that are missing, the more the model must guess — and guesses introduce variability.