Question

A developer wants Copilot to generate a function that validates that a string is a properly formatted international phone number. They open a new file and type the comment: `// validate input`. Copilot suggests a generic non-null string check instead of phone validation. Based on prompt engineering best practices, what is the MOST effective change to get the intended result?

Accepted Answer

Rewrite the comment to be specific about intent, inputs, and expected behavior, e.g. `// Validate that the string is a valid E.164 international phone number, returning true or false`

Answer

Repeat the same `// validate input` comment several times in a row so Copilot weighs the instruction more heavily

Answer

Reject the suggestion and keep pressing the cycle key until Copilot eventually produces phone validation logic

Answer

Switch the file to a different language, since Copilot only generates validation logic reliably in strongly typed languages