diff --git a/crates/hir_ty/src/db.rs b/crates/hir_ty/src/db.rs
index e11fc579e6..1690926ad3 100644
--- a/crates/hir_ty/src/db.rs
+++ b/crates/hir_ty/src/db.rs
@@ -1,4 +1,5 @@
-//! FIXME: write short doc here
+//! The home of `HirDatabase`, which is the Salsa database containing all the
+//! type inference-related queries.
 
 use std::sync::Arc;
 
diff --git a/crates/hir_ty/src/diagnostics.rs b/crates/hir_ty/src/diagnostics.rs
index 86f937e1d3..84fc8ce14d 100644
--- a/crates/hir_ty/src/diagnostics.rs
+++ b/crates/hir_ty/src/diagnostics.rs
@@ -1,4 +1,4 @@
-//! FIXME: write short doc here
+//! Type inference-based diagnostics.
 mod expr;
 mod match_check;
 mod unsafe_check;
diff --git a/crates/hir_ty/src/display.rs b/crates/hir_ty/src/display.rs
index ae3a827808..e7c9dabc22 100644
--- a/crates/hir_ty/src/display.rs
+++ b/crates/hir_ty/src/display.rs
@@ -1,4 +1,6 @@
-//! FIXME: write short doc here
+//! The `HirDisplay` trait, which serves two purposes: Turning various bits from
+//! HIR back into source code, and just displaying them for debugging/testing
+//! purposes.
 
 use std::{
     array,
diff --git a/crates/hir_ty/src/lib.rs b/crates/hir_ty/src/lib.rs
index ef1bdefacb..113234fa48 100644
--- a/crates/hir_ty/src/lib.rs
+++ b/crates/hir_ty/src/lib.rs
@@ -126,14 +126,14 @@ pub fn param_idx(db: &dyn HirDatabase, id: TypeParamId) -> Option<usize> {
     generics(db.upcast(), id.parent).param_idx(id)
 }
 
-pub fn wrap_empty_binders<T>(value: T) -> Binders<T>
+pub(crate) fn wrap_empty_binders<T>(value: T) -> Binders<T>
 where
     T: Fold<Interner, Result = T> + HasInterner<Interner = Interner>,
 {
     Binders::empty(&Interner, value.shifted_in_from(&Interner, DebruijnIndex::ONE))
 }
 
-pub fn make_only_type_binders<T: HasInterner<Interner = Interner>>(
+pub(crate) fn make_only_type_binders<T: HasInterner<Interner = Interner>>(
     num_vars: usize,
     value: T,
 ) -> Binders<T> {
diff --git a/crates/hir_ty/src/primitive.rs b/crates/hir_ty/src/primitive.rs
index 2449addfb7..d7f48c69a5 100644
--- a/crates/hir_ty/src/primitive.rs
+++ b/crates/hir_ty/src/primitive.rs
@@ -1,7 +1,4 @@
-//! Defines primitive types, which have a couple of peculiarities:
-//!
-//! * during type inference, they can be uncertain (ie, `let x = 92;`)
-//! * they don't belong to any particular crate.
+//! A few helper functions for dealing with primitives.
 
 pub use chalk_ir::{FloatTy, IntTy, UintTy};
 pub use hir_def::builtin_type::{BuiltinFloat, BuiltinInt, BuiltinUint};
diff --git a/crates/hir_ty/src/traits.rs b/crates/hir_ty/src/traits.rs
index 7f77e421d4..9936d08033 100644
--- a/crates/hir_ty/src/traits.rs
+++ b/crates/hir_ty/src/traits.rs
@@ -1,9 +1,11 @@
 //! Trait solving using Chalk.
+
 use std::env::var;
 
-use base_db::CrateId;
 use chalk_ir::cast::Cast;
 use chalk_solve::{logging_db::LoggingRustIrDatabase, Solver};
+
+use base_db::CrateId;
 use hir_def::{lang_item::LangItemTarget, TraitId};
 use stdx::panic_context;