Each HTTP API parameter should have a schema associated with it. Most parameters should be string, number, or some other standard data type, but there will be outliers when it comes parameter schema. This is why HTTP API parameters should be centralized and considered as a whole, which is something that can help reduce complexity at the parameter schema level.
Parameter schema should be simple, and when complex, it should use a centralized set of schema–with heavy investment in the simple. The simpler your parameter schema are the simpler it will be for API consumers to turn the knobs and levers you give them for configuring APIs, which is increasingly done by product, support, or sales as well as engineering stakeholders.