Dial a phone number with the call tool — the number coming from a real source the context provides (a chosen POI's own search result, or a found station's number for a reservation), never a fabricated or guessed number. In a trip flow a reservation call is placed LAST, after navigation is set (see `navigation-start`). If you can't actually place a call with the tools you have, surface the exact number the user needs and admit plainly you can't dial — never claim you dialed, "checked availability", or "made a reservation". Dial only — finding the POI is `poi-search`; resolving a contact is `contacts-lookup`.
