diff --git a/vlib/cli/command.v b/vlib/cli/command.v
index c87d92b985..b084bab406 100644
--- a/vlib/cli/command.v
+++ b/vlib/cli/command.v
@@ -2,10 +2,13 @@ module cli
 
 type FnCommandCallback = fn (cmd Command) ?
 
+// str returns the `string` representation of the callback.
 pub fn (f FnCommandCallback) str() string {
 	return 'FnCommandCallback=>' + ptr_str(f)
 }
 
+// Command is a structured representation of a single command
+// or chain of commands.
 pub struct Command {
 pub mut:
 	name            string
@@ -27,6 +30,7 @@ pub mut:
 	args            []string
 }
 
+// str returns the `string` representation of the `Command`.
 pub fn (cmd Command) str() string {
 	mut res := []string{}
 	res << 'Command{'
@@ -55,10 +59,12 @@ pub fn (cmd Command) str() string {
 	return res.join('\n')
 }
 
+// is_root returns `true` if this `Command` has no parents.
 pub fn (cmd Command) is_root() bool {
 	return isnil(cmd.parent)
 }
 
+// root returns the root `Command` of the command chain.
 pub fn (cmd Command) root() Command {
 	if cmd.is_root() {
 		return cmd
@@ -66,6 +72,7 @@ pub fn (cmd Command) root() Command {
 	return cmd.parent.root()
 }
 
+// full_name returns the full `string` representation of all commands int the chain.
 pub fn (cmd Command) full_name() string {
 	if cmd.is_root() {
 		return cmd.name
@@ -73,12 +80,14 @@ pub fn (cmd Command) full_name() string {
 	return cmd.parent.full_name() + ' $cmd.name'
 }
 
+// add_commands adds the `commands` array of `Command`s as sub-commands.
 pub fn (mut cmd Command) add_commands(commands []Command) {
 	for command in commands {
 		cmd.add_command(command)
 	}
 }
 
+// add_command adds `command` as a sub-command of this `Command`.
 pub fn (mut cmd Command) add_command(command Command) {
 	mut subcmd := command
 	if cmd.commands.contains(subcmd.name) {
@@ -89,6 +98,8 @@ pub fn (mut cmd Command) add_command(command Command) {
 	cmd.commands << subcmd
 }
 
+// setup ensures that all sub-commands of this `Command`
+// is linked as a chain.
 pub fn (mut cmd Command) setup() {
 	for mut subcmd in cmd.commands {
 		subcmd.parent = cmd
@@ -96,12 +107,14 @@ pub fn (mut cmd Command) setup() {
 	}
 }
 
+// add_flags adds the array `flags` to this `Command`.
 pub fn (mut cmd Command) add_flags(flags []Flag) {
 	for flag in flags {
 		cmd.add_flag(flag)
 	}
 }
 
+// add_flag adds `flag` to this `Command`.
 pub fn (mut cmd Command) add_flag(flag Flag) {
 	if cmd.flags.contains(flag.name) {
 		println('Flag with the name `$flag.name` already exists')
@@ -110,6 +123,7 @@ pub fn (mut cmd Command) add_flag(flag Flag) {
 	cmd.flags << flag
 }
 
+// parse parses `args` into this structured `Command`.
 pub fn (mut cmd Command) parse(args []string) {
 	if !cmd.disable_flags {
 		cmd.add_default_flags()
@@ -128,6 +142,8 @@ pub fn (mut cmd Command) parse(args []string) {
 	cmd.parse_commands()
 }
 
+// add_default_flags adds the commonly used `-h`/`--help` and
+// `-v`/`--version` flags to the `Command`.
 fn (mut cmd Command) add_default_flags() {
 	if !cmd.disable_help && !cmd.flags.contains('help') {
 		use_help_abbrev := !cmd.flags.contains('h') && cmd.flags.have_abbrev()
@@ -139,6 +155,8 @@ fn (mut cmd Command) add_default_flags() {
 	}
 }
 
+// add_default_commands adds the command functions of the
+// commonly used `help` and `version` flags to the `Command`.
 fn (mut cmd Command) add_default_commands() {
 	if !cmd.disable_help && !cmd.commands.contains('help') && cmd.is_root() {
 		cmd.add_command(help_cmd())
@@ -257,6 +275,8 @@ fn (cmd Command) check_required_flags() {
 	}
 }
 
+// execute_help executes the callback registered
+// for the `-h`/`--help` flag option.
 pub fn (cmd Command) execute_help() {
 	if cmd.commands.contains('help') {
 		help_cmd := cmd.commands.get('help') or { return } // ignore error and handle command normally
diff --git a/vlib/cli/flag.v b/vlib/cli/flag.v
index d9ae118386..4182f76782 100644
--- a/vlib/cli/flag.v
+++ b/vlib/cli/flag.v
@@ -7,6 +7,9 @@ pub enum FlagType {
 	string
 }
 
+// Flag holds information for a command line flag.
+// (flags are also commonly referred to as "options" or "switches")
+// These are typically denoted in the shell by a short form `-f` and/or a long form `--flag`
 pub struct Flag {
 pub mut:
 	flag        FlagType
@@ -20,10 +23,13 @@ mut:
 	found bool
 }
 
+// get_all_found returns an array of all `Flag`s found in the command parameters
 pub fn (flags []Flag) get_all_found() []Flag {
 	return flags.filter(it.found)
 }
 
+// get_bool returns `true` if the flag is set.
+// get_bool returns an error if the `FlagType` is not boolean.
 pub fn (flag Flag) get_bool() ?bool {
 	if flag.flag != .bool {
 		return error('$flag.name: Invalid flag type `$flag.flag`, expected `bool`')
@@ -31,11 +37,15 @@ pub fn (flag Flag) get_bool() ?bool {
 	return flag.value == 'true'
 }
 
+// get_bool returns `true` if the flag specified in `name` is set.
+// get_bool returns an error if the `FlagType` is not boolean.
 pub fn (flags []Flag) get_bool(name string) ?bool {
 	flag := flags.get(name) ?
 	return flag.get_bool()
 }
 
+// get_int returns the `int` value argument of the flag.
+// get_int returns an error if the `FlagType` is not integer.
 pub fn (flag Flag) get_int() ?int {
 	if flag.flag != .int {
 		return error('$flag.name: Invalid flag type `$flag.flag`, expected `int`')
@@ -43,11 +53,15 @@ pub fn (flag Flag) get_int() ?int {
 	return flag.value.int()
 }
 
+// get_int returns the `int` value argument of the flag specified in `name`.
+// get_int returns an error if the `FlagType` is not integer.
 pub fn (flags []Flag) get_int(name string) ?int {
 	flag := flags.get(name) ?
 	return flag.get_int()
 }
 
+// get_float returns the `f64` value argument of the flag.
+// get_float returns an error if the `FlagType` is not floating point.
 pub fn (flag Flag) get_float() ?f64 {
 	if flag.flag != .float {
 		return error('$flag.name: Invalid flag type `$flag.flag`, expected `float`')
@@ -55,11 +69,15 @@ pub fn (flag Flag) get_float() ?f64 {
 	return flag.value.f64()
 }
 
+// get_float returns the `f64` value argument of the flag specified in `name`.
+// get_float returns an error if the `FlagType` is not floating point.
 pub fn (flags []Flag) get_float(name string) ?f64 {
 	flag := flags.get(name) ?
 	return flag.get_float()
 }
 
+// get_string returns the `string` value argument of the flag.
+// get_string returns an error if the `FlagType` is not string.
 pub fn (flag Flag) get_string() ?string {
 	if flag.flag != .string {
 		return error('$flag.name: Invalid flag type `$flag.flag`, expected `string`')
@@ -67,12 +85,15 @@ pub fn (flag Flag) get_string() ?string {
 	return flag.value
 }
 
+// get_string returns the `string` value argument of the flag specified in `name`.
+// get_string returns an error if the `FlagType` is not string.
 pub fn (flags []Flag) get_string(name string) ?string {
 	flag := flags.get(name) ?
 	return flag.get_string()
 }
 
-// parse flag value from arguments and return arguments with all consumed element removed
+// parse parses flag values from arguments and return
+// an array of arguments with all consumed elements removed.
 fn (mut flag Flag) parse(args []string, with_abbrev bool) ?[]string {
 	if flag.matches(args, with_abbrev) {
 		if flag.flag == .bool {
@@ -87,7 +108,7 @@ fn (mut flag Flag) parse(args []string, with_abbrev bool) ?[]string {
 	}
 }
 
-// check if first arg matches flag
+// matches returns `true` if first arg in `args` matches this flag.
 fn (mut flag Flag) matches(args []string, with_abbrev bool) bool {
 	if with_abbrev {
 		return (flag.name != '' && args[0] == '--$flag.name') ||
@@ -125,6 +146,8 @@ fn (mut flag Flag) parse_bool(args []string) ?[]string {
 	return args[1..]
 }
 
+// get returns the `Flag` matching `name` or an error
+// if it can't be found.
 fn (flags []Flag) get(name string) ?Flag {
 	for flag in flags {
 		if flag.name == name {