When I say ?tough” in that instance I mean the scenario is difficult. Odor is clinging in many locations, so it is a difficult scenario and she exhibits signs of being uncertain.
As for you question on the Alert sequence:
What would you like the alert sequence to be and where would you like each of these things in the chain of events, ideally. We can then advise you how to go about doing that, but it is early to be processing in minutia of complex behavior chains.
The strongest alert sequences tend to form organically over time and evolve through offered behaviors. Thus each dog will be slightly different. You can do what you are suggesting with cues and rewarding, but the sequence will be much stronger in stressful/ distracting conditions (which is what we consider field work) if they are behaviors offered freely by Daisy, and then you reward them. If she is rewarded for each time she does a certain behavior (or jackpotted for a new behavior she offers) it is more likely she will continue to increase the likelihood of offering that behavior in the future.
Having behaviors or parts of an alert chain that are known behaviors and are rewarding in of itself (meaning no training or reinforcement are necessary), will mean that later your complex alert chain of behaviors will be much stronger when embedded and strung into the sequence. Does that make sense?
Remember Daisy is a puppy and complex chains are asking a lot at this juncture. We would recommend sticking with offered behaviors and let it evolve. The dig is great, as is the lie down, and she offers them it looks regularly, so keep rewarding those. If there is a trick (such as speak) that you want to incorporate later, practice that away from truffles so that trick becomes one of her favorite things to do, cookie or not.
Best is a relative term, and specific to each dog. A speak can be helpful (for distance yes, and just as another confirmation), but ideally, alerts we have found to be most valuable in the field tend to be precision alerts such as nose touches. This, in conjunction, with an initial alert of location, such as a ?paw? (which Daisy does!,) and a lying down (aka staying at source) tend to be the most valuable in the field.
As for your concern about her knowing you are hiding the truffle:
That is just fine- aka do not worry. You are building drive actually if she is excited by the prospect of playing the game. That is good!