Suggest the Fix or Link to It
A good error says what to do next, not just that the call failed. Append the remedy: the command to run, the option to set, or a docs link. The reader is stuck; this message is your one chance to unstick them.
Incorrect (states the failure, offers no path forward):
throw new Error("No config file found");Correct (names the failure and the next action):
throw new Error(
`No config file found at "${path}". ` +
`Run \`mytool init\` to create one, or pass --config <path>. ` +
`See https://mytool.dev/config`,
);