diff --git a/src/cmd/cgo/doc.go b/src/cmd/cgo/doc.go
index 83f1ba4..f6a14ae 100644
--- a/src/cmd/cgo/doc.go
+++ b/src/cmd/cgo/doc.go
@@ -6,7 +6,8 @@
 
 Cgo enables the creation of Go packages that call C code.
 
-Usage: go tool cgo [compiler options] file.go
+Usage:
+	go tool cgo [compiler options] file.go
 
 The compiler options are passed through uninterpreted when
 invoking gcc to compile the C parts of the package.
diff --git a/src/cmd/cov/doc.go b/src/cmd/cov/doc.go
index edeb915..a5fc003 100644
--- a/src/cmd/cov/doc.go
+++ b/src/cmd/cov/doc.go
@@ -6,12 +6,14 @@
 
 Cov is a rudimentary code coverage tool.
 
+Usage:
+	go tool cov [-lsv] [-g substring] [-m minlines] [6.out args]
+
 Given a command to run, it runs the command while tracking which
 sections of code have been executed.  When the command finishes,
 cov prints the line numbers of sections of code in the binary that
 were not executed.   With no arguments it assumes the command "6.out".
 
-Usage: go tool cov [-lsv] [-g substring] [-m minlines] [6.out args]
 
 The options are:
 
diff --git a/src/cmd/go/doc.go b/src/cmd/go/doc.go
index 51514cb..8df57ff 100644
--- a/src/cmd/go/doc.go
+++ b/src/cmd/go/doc.go
@@ -5,7 +5,9 @@
 /*
 Go is a tool for managing Go source code.
 
-Usage: go command [arguments]
+Usage:
+
+	go command [arguments]
 
 The commands are:
 
@@ -49,11 +51,13 @@
 of source files specifying a single package.
 
 When the command line specifies a single main package,
-build writes the resulting executable to output (default a.out).
+build writes the resulting executable to output.
 Otherwise build compiles the packages but discards the results,
 serving only as a check that the packages can be built.
 
-The -o flag specifies the output file name.
+The -o flag specifies the output file name.  If not specified, the
+name is packagename.a (for a non-main package) or the base
+name of the first source file (for a main package).
 
 The build flags are shared by the build, install, run, and test commands:
 
@@ -389,6 +393,9 @@
 
 GOPATH environment variable
 
+The Go path is used to resolve import statements.
+It is implemented by and documented in the go/build package.
+
 The GOPATH environment variable lists places to look for Go code.
 On Unix, the value is a colon-separated string.
 On Windows, the value is a semicolon-separated string.
@@ -472,7 +479,7 @@
 each of which can match any string, including the empty string and
 strings containing slashes.  Such a pattern expands to all package
 directories found in the GOPATH trees with names matching the
-patterns.  For example, encoding/... expands to all package
+patterns.  For example, encoding/... expands to all packages
 in subdirectories of the encoding tree, while net... expands to
 net and all its subdirectories.
 
diff --git a/src/cmd/go/main.go b/src/cmd/go/main.go
index a56910e..3a0f7a0 100644
--- a/src/cmd/go/main.go
+++ b/src/cmd/go/main.go
@@ -141,7 +141,9 @@
 
 var usageTemplate = `Go is a tool for managing Go source code.
 
-Usage: go command [arguments]
+Usage:
+
+	go command [arguments]
 
 The commands are:
 {{range .}}{{if .Runnable}}
diff --git a/src/cmd/pack/doc.go b/src/cmd/pack/doc.go
index 6cbc357..8b17f3c 100644
--- a/src/cmd/pack/doc.go
+++ b/src/cmd/pack/doc.go
@@ -12,7 +12,8 @@
 Go type information from the files in the archive; that section is
 used by the compiler when importing the package during compilation.
 
-Usage: go tool pack [uvnbailogS][mrxtdpq][P prefix] archive files ...
+Usage:
+	go tool pack [uvnbailogS][mrxtdpq][P prefix] archive files ...
 
 The new option 'g' causes pack to maintain the __.PKGDEF section
 as files are added to the archive.
diff --git a/src/cmd/prof/doc.go b/src/cmd/prof/doc.go
index 08aa086..0072f9a 100644
--- a/src/cmd/prof/doc.go
+++ b/src/cmd/prof/doc.go
@@ -16,8 +16,8 @@
 asleep or waiting for I/O.  Each thread contributes equally to the
 statistics.
 
-
-Usage: prof -p pid [-t total_secs] [-d delta_msec] [6.out args ...]
+Usage:
+	go tool prof -p pid [-t total_secs] [-d delta_msec] [6.out args ...]
 
 The output modes (default -h) are:
 
diff --git a/src/cmd/yacc/doc.go b/src/cmd/yacc/doc.go
index 9874a2a..4a2c2a3 100644
--- a/src/cmd/yacc/doc.go
+++ b/src/cmd/yacc/doc.go
@@ -4,10 +4,13 @@
 
 /*
 
-Yacc is a version of yacc for Go. It is run with the command
-	go tool yacc args...
+Yacc is a version of yacc for Go.
 It is written in Go and generates parsers written in Go.
 
+Usage:
+
+	go tool yacc args...
+
 It is largely transliterated from the Inferno version written in Limbo
 which in turn was largely transliterated from the Plan 9 version
 written in C and documented at