diff --git a/rust/repositories.bzl b/rust/repositories.bzl
index 4762a798a8..6a6630143d 100644
--- a/rust/repositories.bzl
+++ b/rust/repositories.bzl
@@ -192,6 +192,8 @@ def rust_register_toolchains(
         hub_name (str, optional): The name of the bzlmod hub repository for toolchains.
         compact_windows_names (bool): Whether or not to produce compact repository names for windows
             toolchains. This is to avoid MAX_PATH issues.
+        toolchain_triples (dict[str, str], optional): Mapping of rust target triple -> repository name to create.
+        extra_toolchain_infos: (dict[str, dict], optional): Mapping of information about extra toolchains which were created outside of this call, which should be added to the hub repo.
     """
     if not rustfmt_version:
         if len(versions) == 1:
@@ -1142,6 +1144,8 @@ def rust_repository_set(
         aliases (dict): Replacement names to use for toolchains created by this macro.
         compact_windows_names (bool): Whether or not to produce compact repository names for windows
             toolchains. This is to avoid MAX_PATH issues.
+    Returns:
+        dict[str, dict]: A dict of informations about all generated toolchains.
     """
 
     all_toolchain_details = {}