Avoiding Overlap and Trigger Confusion
What happens when two skills could both plausibly apply to the same task, and how a clear boundary in each description prevents the mix-up.
Two shelf labels that say almost the same thing
Picture a library where two different shelves both have labels reading "books about history." A visitor looking for something specific has no way to know which shelf actually has what they need, and might end up checked at the wrong one entirely. The problem isn't that either shelf is badly organized on its own. It's that neither label says anything the other doesn't already say.
The same failure shows up between skills whose descriptions overlap too much: given a task that could plausibly fit either one, there's no reliable way to know which one should actually take it, and sometimes neither does, or the wrong one does.
Where this actually tends to happen
Overlap creeps in gradually, not all at once. Two skills built for genuinely different purposes can end up with descriptions that both mention the same broad word, like "API" or "review," without either one narrowing down to what specifically makes it different from the other.
Both descriptions are true of almost any task involving an API. Nothing here tells Claude, or a person reading the list, which one to reach for in a given situation.
Same general topic, but each description names a distinct situation. A task clearly belongs to one or the other, not both.
A pattern worth borrowing: say what to skip, not just what to use
For two skills that sit close to each other in subject matter, it often helps for each description to name the boundary explicitly, not just what it's for, but what nearby situation it's deliberately not for. That single addition removes almost all the ambiguity a shared topic word would otherwise create.
If you have access to more than one existing skill, pick two whose topics sound at all similar. Read only their descriptions, side by side, and ask: given a task right on the boundary between them, would it be obvious which one to use? If not, that boundary is exactly what's missing from both.