Agreed, I find per-parameter docs useful in dynamic languages such as python, or to a lesser extent useful when the type system is weaker (in C), but in Rust I seldom find them useful. This can be useful to express constraints not present in the type system, for instance `fn matmul(a: Matrix<f64>, b: Matrix<f64>) -> Matrix<f64>` will benefit from a documentation describing the constraints and guarantees on the number of rows and cols of each matrix, since this cannot be expressed in the type system (yet).