So I saw this idea posted in another forum thread, and I'm curious how valid it is. I suspect less than the original poster thought it was.
You're playing a rigger or decker (because RAW page 221 states that your Commlink has "got all of the necessary software already loaded, but unlike a cyberdeck it has no space for cyberprograms or other hacking tools.", a topic for another thread.) You buy a rating 4 Agent program, the highest you can get at character creation at availability rating X3. That agent is run in one of your program slots on your Deck or RCC (let's ignore the vague definition of how many non-autosoft programs the RCC can run, that's another thread.) We'll assume most of your important wireless enabled gear is slaved to that same device.
Now you set that Agent to always take the Full Matrix Defense Action, and if it has any other actions left, to analyze icons looking for trouble to report to you. IE: "Sir, you appear to be in a fire fight, but I regret to inform you that you have a strange MARK on your Ares Predator V." For the purposes of the following questions, I'm more concerned with the first part of this task: Full Matrix Defense.
Now normally, if you run an agent by itself, it generates a Persona from your device (the Deck or RCC), which it replaces/absorbs, much as a normal user replaces the device icon with a persona icon. See page 235: "Agents running alone on a device replace the device icon the same way a living user does. If you’re running an agent along with your persona, it appears with its own separate persona, even though you’re using the same device." For the purposes of questions 1 and 2, the device is assumed to be running without an active user as well. Question 3 assumes that you are also logged into the matrix with a persona.
So, here are the questions:
1) The rating 4 Agent effectively has a 4 willpower. Thanks to the Full Matrix Defense, it will get to add this 4 dice to any defense tests it gets to make, but does this also extend to to the device it's running on?
My thoughts: Because it's persona has absorbed the Deck/RCC, I imagine it does defend that device, as any matrix attacks against the device will be against the agent's icon. You can't target the deck separately.
2) Assuming 1 is "yes, it applies" what about attacks on other icons you own? Does it protect your wireless enabled gun which is slaved to the deck/RCC? I assume no, because if someone attacks the gun, "You" are making the roll for your gun, not the agent as it is not directly targeted, and "full matrix defense" isn't a matrix attribute the gun can gain from slaving. Nor is the Agent the gun's owner, so it has no reason to be involved.
3) Now let's complicate things and say your character is also on the matrix, and therefore has a Persona. Your persona has absorbed the Deck, and the Agent is given it's own separate Persona Icon. In this case, I'm not sure the 4 Dice bonus from matrix full defense applies to anything other than the agent. It's now possible for matrix attackers to target your icon instead of the agent's icon, and therefore inflict damage onto your deck without the agent being involved.