What is success condition?
An ad-hoc run carries an explicit success spec alongside its prompt: a status text match, a URL substring, visible text on the page, the presence of extracted data, or a boolean combination of those. The run ends when the condition holds or the step budget runs out.
Why it matters
Letting a planner decide whether it succeeded is how automation reports a green run that did nothing. An external, checkable condition is what makes a result trustworthy — and it is required on the free-text form for exactly that reason.