I was wondering, just how specific (and helpful) must an answer to Posing the Silent Question be? Let's say I cast Posing the Silent Question and ask you, "Where do you have your stash of money hidden?" What's an acceptable answer?
"In Paris."
"In Monmartre."
"On the Boulevard of Kings."
"In my house on the Boulevard of Kings."
"In my house on the second floor."
"In my solar."
"In my solar, underneath the large chest in the corner."
"In my solar, underneath the large chest in the corner, beneath the loose floorboard, in a plain leather bag."
Literally, all of these statements may be true. But which one is given as an answer? Clearly, the caster wants as precise an answer as possible. But does the spell read intent, or just the words of the question asked? And if just the words, how specific must it get?
Also, what if the question is vague enough to have more than one answer? Let's say you ask the count, "where is your horse?" Your question refers to his prized stallion that he rides everywhere. But being a rich man, he has many horses in addition to his prized stallion. Some are in his stable, others are being ridden around his lands, most he has no idea where they are. But again, does the spell read intentions? Could the answer be, "which horse are you talking about?" or "many places around the county." Does it matter if the count knows full well which horse you mean, but the question is nonetheless still vague?
Remember, the caster is not "literally" asking a question and forcing the target to answer (that would be Rego Mentem). The caster is learning a single fact by "peeking" into the target's mind (Intellego Mentem). It's useful to think of the target's mind as an encyclopedia, of which the caster can read a single entry. So, in the first example you gave, the caster would learn the most detailed answer available to the target, all the way to the leather bag.
Note that it's still possible to look for the wrong type of information. If most of the wealth of the target is in ... silk, let's say, and the caster looks for information about the target's silver, he'll probably only learn about the silver. If the caster looks for information about a knight's "horse", he'll most likely get information about his warhorse; he may or may not get information about his palfrey(s), depending on how the knight thinks about his warhorse ("the best of my horses" or "my one real horse"). It's a bit like consulting an index (or google) looking for the "wrong" word. Sometimes the one gets the "right" reference anyway, sometimes one doesn't. As a SG, I'd adjudicate doubtful cases with an Int+Finesse roll or Per+Finesse, to check if the magus was smart and/or diligent and/or perceptive enough to "search correctly", even though the player may not have done so.
Such an Int+Finesse or Per+Finesse might also be used to see if the magus can capture half-remembered information ("uh, my scarf from ten years ago? where would that be?") or somewhat tangential information ("the silver is in my room, in the (trapped, hehe!) chest.")
I agree with ezzelino, it depends on how the targets identifies the subject of the question.
Where is your horse? -> it refers to what the targets thinks as his/her horse. It also refers to the place he/she thinks about when thinking about the horse.
Where is your money? -> If the target is in Marseille and the money is in Budapest, the answer would likely be "In Budapest". If the money is in the target's house, a few blocks away, the answer would be "In my house [there]".
In general, I'd come down on providing as reasonably complete and truthful an answer as the target can give, with exceptions.
There are probably Mentem spells out there designed to screw with this spell in a number of different ways.
Some Personality Traits and/or Virtues/Flaws may influence the answer. Extreme values of "Helpful" or "Secretive" for example, or the Flaws Indiscreet, Incomprehensible or Simple-Minded may make a difference in the quality of the answer.
Demonic possession would make a difference.
Using this spell on some targets may void the warranty. The more exotic/extreme Criamon and Merinita magi come to mind - imagine posing the wrong question to a Criamon and getting an Adulteration as an answer.