There is a recognised escalation ladder in the language. Watching with interest is mild; watching with a sense of urgency is firmer; describing moves as excessive, one-sided or disorderly, and saying that all options are on the table, is close to the edge of central-bank-intervention itself.
It is cheap and repeatable, which is also its weakness. Repeated warnings without action lose their effect, and traders eventually treat them as a free option to keep pushing until something is actually sold.
Because the reaction is immediate and headline-driven, verbal intervention is a recurring source of the sudden two-way moves and spread-widening that catch stops on otherwise quiet sessions.
Example: an official calls recent currency moves rapid and one-sided. The pair drops 60 pips in a minute, then recovers 45 of them over the next hour once no actual flow appears.
Related: central-bank-intervention, spread-widening, economic-calendar, fx-reserves