As we’ve probably learned over the years, cards generally do exactly what their Gatherer texts say. But some people still get confused. A major thing that I’ve seen trip people up is confusion about counters. Some people think that a static +1/+1 bonus (like from Spear of Heliod, or Ajani’s Presence) also counts as a counter. But that’s not true. There’s only a counter involved if the card says to put a counter on it. Just a general bonus from a card doesn’t mean that you’re putting any counters on the card.
For instance, if you cast Ajani’s Presence on two of your creatures, they’re just getting +1/+1 (and indestructible) until end of turn. They’re not getting a +1/+1 counter, so you can’t move it to another creature with Bioshift and cards like Chronicler of Heroes will not count it towards its triggered ability. So remember: unless the card says that you’re putting a counter on the card, there’s no counters involved, so don’t try to count on things that aren’t counters- because they don’t count.