Add a `prepareInvocation` for summarize notification tool

[alexr00]

Looks like I missed this one.

[eleanorjboyd]

What is the expected outcome here? Seeing this when I searched:

[TylerLeonhardt]

It's the Fetching item #... text

[aiday-mar]

The prepare invocation text is there as expected. But the notification summary is not correct, investigating.