Adding is always scoped to one agent, and always checked with the provider before it is charged.
If the check fails you see Provider unavailable. No money moves, and no purchase record is created — a failed availability check is not a purchase and does not appear in payment history.
Only one unresolved purchase can exist for the same agent and capability. A duplicate attempt is blocked before it can charge or provision anything. If a settlement result is unclear, the duplicate stays blocked until it is reconciled — deliberately, so you cannot be billed twice for one thing.
A confirmed payment is a milestone. The purchase completes only when the capability is delivered. If payment settled and delivery did not, that is a refund case, not a silent loss. See Refunds and failed delivery.
Adding a social or application account starts a live signup rather than an instant provisioning. Those usually need an email address or phone number already on the agent.