Thanks for bringing this to my attention. We're actually in the middle of a documentation audit this week, and this is exactly the type of issue we want to flag.
Toolchain tutorial contradicts ToolchainInfo reference documentation
### Description of the problem / feature request:

Reference documentation:
https://docs.bazel.build/versions/master/skylark/lib/platform_common.html#ToolchainInfo
> The provider constructor for ToolchainInfo. The constructor takes the type of the toolchain, and a map of the toolchain's data.

Tutorial:
https://docs.bazel.build/versions/master/toolchains.html#creating-a-toolchain-rule
```
def _my_toolchain_impl(ctx):
  toolchain = platform_common.ToolchainInfo(
    compiler = ctx.attr.compiler,
    system_lib = ctx.attr.system_lib,
    arch_flags = ctx.attr.arch_flags,
  )
  return [toolchain]
```

The tutorial doesn't call `ToolchainInfo` with the type of the toolchain at all, and doesn't pass in a map, just keyword arguments. I think the tutorial documents the correct usage.

src/main/java/com/google/devtools/build/lib/skylarkbuildapi/platform/PlatformCommonApi.java
src/main/java/com/google/devtools/build/lib/skylarkbuildapi/platform/PlatformCommonApi.java
diff --git a/src/main/java/com/google/devtools/build/lib/skylarkbuildapi/platform/PlatformCommonApi.java b/src/main/java/com/google/devtools/build/lib/skylarkbuildapi/platform/PlatformCommonApi.java
index 5db6e4652af868..e07a30b3d20c7f 100644
--- a/src/main/java/com/google/devtools/build/lib/skylarkbuildapi/platform/PlatformCommonApi.java
+++ b/src/main/java/com/google/devtools/build/lib/skylarkbuildapi/platform/PlatformCommonApi.java
@@ -27,8 +27,8 @@ public interface PlatformCommonApi {
   @SkylarkCallable(
       name = "TemplateVariableInfo",
       doc =
-          "The provider used to retrieve the provider that contains the template variables "
-              + "defined by a particular toolchain, for example by calling "
+          "The provider used to retrieve the provider that contains the template variables defined"
+              + " by a particular toolchain, for example by calling "
               + "ctx.attr._cc_toolchain[platform_common.TemplateVariableInfo].make_variables[<name>]",
       structField = true)
   ProviderApi getMakeVariableProvider();
@@ -36,8 +36,8 @@ public interface PlatformCommonApi {
   @SkylarkCallable(
       name = "ToolchainInfo",
       doc =
-          "The provider constructor for ToolchainInfo. The constructor takes the type of the "
-              + "toolchain, and a map of the toolchain's data.",
+          "The provider constructor for ToolchainInfo. The constructor takes a map of the "
+              + "toolchain's data.",
       structField = true)
   ProviderApi getToolchainInfoConstructor();
 
