Improve documentation for borrowed-box lint

clippy_lints/src/types/mod.rs

@@ -167,8 +167,9 @@ declare_clippy_lint! {
  /// Check the [Box documentation](https://doc.rust-lang.org/std/boxed/index.html) for more information.
  ///
  /// ### Why is this bad?
- /// Any `&Box<T>` can also be a `&T`, which is more
- /// general.
+ /// A `&Box<T>` parameter requires the function caller to box `T` first before passing it to a function.
+ /// Using `&T` defines a concrete type for the parameter and generalizes the function, this would also
+ /// auto-deref to `&T` at the function call site if passed a `&Box<T>`.
  ///
  /// ### Example
  /// ```rust,ignore