diff --git a/doc/preserves-tool.md b/doc/preserves-tool.md
index f9f6f61..b6413ad 100644
--- a/doc/preserves-tool.md
+++ b/doc/preserves-tool.md
@@ -5,20 +5,29 @@ title: preserves-tool
 The `preserves-tool` program is a swiss army knife for working with
 Preserves documents.
 
-    preserves-tools 1.0.0
+```
+preserves-tool 4.992.0
+Swiss-army knife tool for working with Preserves data.
+See https://preserves.dev/. If no subcommand is specified, the default
+subcommand will be `convert`.
 
-    USAGE:
-        preserves-tool <SUBCOMMAND>
+USAGE:
+    preserves-tool [OPTIONS]
+    preserves-tool <SUBCOMMAND>
 
-    FLAGS:
-        -h, --help       Print help information
-        -V, --version    Print version information
+OPTIONS:
+    -h, --help       Print help information
+    -V, --version    Print version information
 
-    SUBCOMMANDS:
-        completions
-        convert
-        help           Print this message or the help of the given subcommand(s)
-        quote
+OPTIONS FOR DEFAULT SUBCOMMAND convert:
+    [...]
+
+SUBCOMMANDS:
+    completions
+    convert
+    help           Print this message or the help of the given subcommand(s)
+    quote
+```
 
 ## Installation
 
@@ -31,9 +40,10 @@ Then, `cargo install preserves-tools`.
 
 The tool includes three subcommands.
 
-### `preserves-tool convert`
+### `preserves-tool convert`, `preserves-tool`
 
-This is the main tool. It can
+This is the main tool, and is also the default if no subcommand is
+explicitly specified. It can
 
  - translate between the various Preserves text and binary document
    syntaxes;
@@ -48,38 +58,45 @@ This is the main tool. It can
     USAGE:
         preserves-tool convert [FLAGS] [OPTIONS]
 
-    FLAGS:
-            --collect
-            --escape-spaces
-        -h, --help             Prints help information
-        -V, --version          Prints version information
-
     OPTIONS:
-            --bundle <filename>...
-        -c, --commas <commas>
+            --bundle <filename>
+
+
+        -c, --commas <COMMAS>
                 [default: none] [possible values: none, separating, terminating]
 
-            --indent <on/off>
-                [default: on] [possible values: disabled, no, n, off, 0, false,
-                enabled, yes, y, on, 1, true]
+            --collect
 
-        -i, --input-format <input-format>
+
+            --escape-spaces
+
+
+        -h, --help
+                Print help information
+
+        -i, --input-format <INPUT_FORMAT>
                 [default: auto-detect] [possible values: auto-detect, text, binary]
 
-            --limit <limit>
-        -o, --output-format <output-format>
-                [default: text] [possible values: text, binary, unquoted]
-            --read-annotations <on/off>
-                [default: on] [possible values: disabled, no, n, off, 0, false,
-                enabled, yes, y, on, 1, true]
+            --indent <on/off>
+                [default: on] [possible values: disabled, enabled]
 
-            --schema <schema>
-            --select <select-expr>             [default: *]
-            --select-output <select-output>
+            --limit <LIMIT>
+
+
+        -o, --output-format <OUTPUT_FORMAT>
+                [default: text] [possible values: text, binary, unquoted]
+
+            --read-annotations <on/off>
+                [default: on] [possible values: disabled, enabled]
+
+            --select <SELECT_EXPR>
+                [default: *]
+
+            --select-output <SELECT_OUTPUT>
                 [default: sequence] [possible values: sequence, set]
+
             --write-annotations <on/off>
-                [default: on] [possible values: disabled, no, n, off, 0, false,
-                enabled, yes, y, on, 1, true]
+                [default: on] [possible values: disabled, enabled]
 
 ### `preserves-tool quote`
 
@@ -101,12 +118,10 @@ preserves-tool-quote
 USAGE:
     preserves-tool quote [OPTIONS] <SUBCOMMAND>
 
-FLAGS:
-    -h, --help       Print help information
-    -V, --version    Print version information
-
 OPTIONS:
-    -o, --output-format <OUTPUT_FORMAT>    [default: text] [possible values: text, binary, unquoted]
+    -h, --help                             Print help information
+    -o, --output-format <OUTPUT_FORMAT>    [default: text] [possible values: text,
+                                           binary, unquoted]
 
 SUBCOMMANDS:
     byte-string
@@ -119,32 +134,28 @@ SUBCOMMANDS:
 preserves-tool-quote-string
 
 USAGE:
-    preserves-tool quote string [FLAGS] [OPTIONS]
-
-FLAGS:
-        --escape-spaces
-    -h, --help                  Print help information
-        --include-terminator
-    -V, --version               Print version information
+    preserves-tool quote string [OPTIONS]
 
 OPTIONS:
-        --input-terminator <INPUT_TERMINATOR>    [default: eof] [possible values: eof, newline, nul]
+        --escape-spaces
+    -h, --help                                   Print help information
+        --include-terminator
+        --input-terminator <INPUT_TERMINATOR>    [default: eof] [possible values:
+                                                 eof, newline, nul]
 ```
 
 ```
 preserves-tool-quote-symbol
 
 USAGE:
-    preserves-tool quote symbol [FLAGS] [OPTIONS]
-
-FLAGS:
-        --escape-spaces
-    -h, --help                  Print help information
-        --include-terminator
-    -V, --version               Print version information
+    preserves-tool quote symbol [OPTIONS]
 
 OPTIONS:
-        --input-terminator <INPUT_TERMINATOR>    [default: eof] [possible values: eof, newline, nul]
+        --escape-spaces
+    -h, --help                                   Print help information
+        --include-terminator
+        --input-terminator <INPUT_TERMINATOR>    [default: eof] [possible values:
+                                                 eof, newline, nul]
 ```
 
 ```
@@ -153,9 +164,8 @@ preserves-tool-quote-byte-string
 USAGE:
     preserves-tool quote byte-string
 
-FLAGS:
-    -h, --help       Print help information
-    -V, --version    Print version information
+OPTIONS:
+    -h, --help    Print help information
 ```
 
 ### `preserves-tool completions`
@@ -176,12 +186,11 @@ Multiple shell dialects are supported (courtesy of
 preserves-tool-completions
 
 USAGE:
-    preserves-tool completions <dialect>
+    preserves-tool completions <SHELL>
 
 ARGS:
-    <dialect>    [possible values: bash, zsh, power-shell, fish, elvish]
+    <SHELL>    [possible values: bash, elvish, fish, powershell, zsh]
 
-FLAGS:
-    -h, --help       Print help information
-    -V, --version    Print version information
+OPTIONS:
+    -h, --help    Print help information
 ```
diff --git a/implementations/rust/preserves-tools/src/bin/preserves-tool.rs b/implementations/rust/preserves-tools/src/bin/preserves-tool.rs
index a95234e..7909c11 100644
--- a/implementations/rust/preserves-tools/src/bin/preserves-tool.rs
+++ b/implementations/rust/preserves-tools/src/bin/preserves-tool.rs
@@ -177,9 +177,16 @@ enum Subcommand {
 #[derive(Clone, Debug, Parser)]
 #[clap(name = "preserves-tool")]
 #[clap(version)]
+#[clap(args_conflicts_with_subcommands = true)]
+/// Swiss-army knife tool for working with Preserves data.
+/// See https://preserves.dev/.
+/// If no subcommand is specified, the default subcommand will be `convert`.
 struct CommandLine {
     #[clap(subcommand)]
-    command: Subcommand,
+    command: Option<Subcommand>,
+
+    #[clap(flatten, next_help_heading="OPTIONS FOR DEFAULT SUBCOMMAND convert")]
+    convert: Convert,
 }
 
 fn print_completions<G: Generator>(gen: G, cmd: &mut Command) {
@@ -189,12 +196,15 @@ fn print_completions<G: Generator>(gen: G, cmd: &mut Command) {
 fn main() -> io::Result<()> {
     let args = CommandLine::parse();
     Ok(match args.command {
-        Subcommand::Completions { shell } => {
-            let mut cmd = CommandLine::into_app();
-            print_completions(shell, &mut cmd);
+        Some(subcommand) => match subcommand {
+            Subcommand::Completions { shell } => {
+                let mut cmd = CommandLine::into_app();
+                print_completions(shell, &mut cmd);
+            }
+            Subcommand::Convert(c) => convert(c)?,
+            Subcommand::Quote(q) => quote(q)?,
         }
-        Subcommand::Convert(c) => convert(c)?,
-        Subcommand::Quote(q) => quote(q)?,
+        None => convert(args.convert)?,
     })
 }