register_tool is silently overridden by actual modules

Code

#![feature(register_tool)]
#![register_tool(tokio)]
use tokio;

#[tokio::tool_attr]
fn main() {}

Current output

error[E0433]: failed to resolve: could not find `tool_attr` in `tokio`
 --> src/main.rs:5:10
  |
5 | #[tokio::tool_attr]
  |          ^^^^^^^^^ could not find `tool_attr` in `tokio`

For more information about this error, try `rustc --explain E0433`.

Desired output

error[E0433]: failed to resolve: could not find `tool_attr` in `tokio`
 --> src/main.rs:5:10
  |
5 | #[tokio::tool_attr]
  |          ^^^^^^^^^ could not find `tool_attr` in `tokio`
 note: tool namespace overridden by actual module

For more information about this error, try `rustc --explain E0433`.

Rationale and extra context

No response

Other cases

Rust Version

1.87.0-nightly

(2025-02-26 00f245915b0c7839d42c)

Anything else?

No response

Reproduce the issue with the provided register_tool and tokio module example on the stated nightly Rust version. Trace the compiler's tool-namespace resolution and diagnostic path; done means the unresolved tool attribute still reports E0433 and adds the requested note that the tool namespace was overridden by an actual module.