viaClientElicitation

Asks the MCP client's user (via elicit) to approve the call. When the client can't elicit — in-process calls, clients without the capability — fallback decides, and with no fallback the call is declined.

Note the trust model: this asks whoever is at the client (e.g. the desktop), which is the right person for "did you mean to do this?" but not a defence against a compromised client. For that, confirm on the phone with your own ToolCallConfirmer.