reduce overlong lines
diff --git a/src/building/bootstrapping/writing-tools-in-bootstrap.md b/src/building/bootstrapping/writing-tools-in-bootstrap.md
index 8250a6f..8ac2e6b 100644
--- a/src/building/bootstrapping/writing-tools-in-bootstrap.md
+++ b/src/building/bootstrapping/writing-tools-in-bootstrap.md
@@ -19,11 +19,16 @@
Use this for tools that use the `rustc_private` mechanism,
and thus depend on the locally built `rustc` and its rlib artifacts.
- This is more complex than the other modes because the tool must be built with the same compiler used for `rustc` and placed in the "stageN-tools" directory.
- When you choose `Mode::ToolRustcPrivate`, `ToolBuild` implementation takes care of this automatically.
+ This is more complex than the other modes,
+ because the tool must be built with the same compiler used for `rustc`,
+ and placed in the "stageN-tools" directory.
+ When you choose `Mode::ToolRustcPrivate`,
+ `ToolBuild` implementation takes care of this automatically.
If you need to use the builder’s compiler for something specific,
you can get it from `ToolBuildResult`, which is returned by the tool's [`Step`].
-Regardless of the tool type you must return `ToolBuildResult` from the tool’s [`Step`] implementation and use `ToolBuild` inside it.
+Regardless of the tool type,
+you must return `ToolBuildResult` from the tool’s [`Step`] implementation,
+and use `ToolBuild` inside it.
[`Step`]: https://doc.rust-lang.org/nightly/nightly-rustc/bootstrap/core/builder/trait.Step.html
