Poorly written rules are frustrating. Ambiguity can lead to disagreements or confusion. But the meaning of specific terms or abilities isn’t always a detriment to gameplay.
When a game purposefully uses non-standard terms for standard game mechanics, it’s a strain on any player’s brain, forced to unnecessarily learn. When left open-for-interpretation, magic or other abilities can be wildly misused, derailing a game from its intended experience. However, the entire concept of tabletop RPGs is based on the idea that the GM is there to make judgement calls. If a designer embraces this concept, and employs the unpredictability of meaning into their game’s mechanics, it can create a feeling of empowered ownership for the players interpreting those meanings.
An excellent example of this type of uncertainty at work is the game The Fall of Magic. The entire game is based around the abstract prompts presented by the constantly unraveling scroll. What exactly is a crabsinger? It’s completely up to you! This type of mechanic gives the players direction, but ultimate agency in the game, resulting in a completely unique experience.
Tabletop RPGs are all about being creative, flexing your imagination, and using the rule-of-cool on the rules as written. Don’t confuse your players with ambiguous mechanics. Include all of the information required to play your game, leaving only purposefully placed blanks for the players to fill in on their own!