It's impossible to answer unless you have a *100% complete search tool*.
No sytem can know everything. It doesn't matter how many tools you give it. It's always wrong to force binary True / False without shades of "I don't know"
Thanks; I didn't spot that they disabled tools in the harness. Also they don't provide an "out" to allow the models to express uncertainty so the instructions force a guess to be made.
As an aside though it's still funny that the two tools WITH search also disagreed.
No sytem can know everything. It doesn't matter how many tools you give it. It's always wrong to force binary True / False without shades of "I don't know"