diff --git a/apps/wordcraft-cli/src/main.rs b/apps/wordcraft-cli/src/main.rs
index 8f743c47a..e9b86da24 100644
--- a/apps/wordcraft-cli/src/main.rs
+++ b/apps/wordcraft-cli/src/main.rs
@@ -96,6 +96,58 @@ fn arg_value(args: &[String], name: &str) -> Option<String> {
     args.iter().position(|a| a == name).and_then(|i| args.get(i + 1)).cloned()
 }
 
+enum OptionArg<'a> {
+    Absent,
+    Duplicate,
+    MissingValue,
+    Value(&'a str),
+}
+
+fn find_option_arg<'a>(args: &'a [String], name: &str) -> OptionArg<'a> {
+    let mut matches = args.iter().enumerate().filter(|(_, a)| *a == name);
+    let Some((i, _)) = matches.next() else {
+        return OptionArg::Absent;
+    };
+    if matches.next().is_some() {
+        return OptionArg::Duplicate;
+    }
+    match args.get(i + 1) {
+        None => OptionArg::MissingValue,
+        Some(val) if val.starts_with("--") => OptionArg::MissingValue,
+        Some(val) => OptionArg::Value(val.as_str()),
+    }
+}
+
+fn parse_page_arg(command: &str, args: &[String]) -> Result<Option<u64>, String> {
+    match find_option_arg(args, "--page") {
+        OptionArg::Absent => Ok(None),
+        OptionArg::Duplicate => Err(format!("{command}: duplicate --page option")),
+        OptionArg::MissingValue => Err(format!("{command}: --page requires a value")),
+        OptionArg::Value(val) => {
+            let n = val.parse::<u64>().map_err(|_| format!("{command}: invalid --page `{val}`: not a valid integer"))?;
+            if n == 0 {
+                return Err(format!("{command}: invalid --page `0`: page numbers start at 1"));
+            }
+            Ok(Some(n))
+        }
+    }
+}
+
+fn parse_scale_arg(command: &str, args: &[String]) -> Result<Option<f64>, String> {
+    match find_option_arg(args, "--scale") {
+        OptionArg::Absent => Ok(None),
+        OptionArg::Duplicate => Err(format!("{command}: duplicate --scale option")),
+        OptionArg::MissingValue => Err(format!("{command}: --scale requires a value")),
+        OptionArg::Value(val) => {
+            let scale = val.parse::<f64>().map_err(|_| format!("{command}: invalid --scale `{val}`: not a number"))?;
+            if !scale.is_finite() || scale <= 0.0 {
+                return Err(format!("{command}: invalid --scale `{val}`: scale must be a positive number"));
+            }
+            Ok(Some(scale))
+        }
+    }
+}
+
 #[derive(Clone, Copy)]
 struct OptionSpec {
     name: &'static str,
@@ -267,14 +319,16 @@ fn run(args: &[String]) -> Result<(), Failure> {
         "render" => {
             validate_options("render", &rest, RENDER_OPTIONS)?;
             let (i, o) = (pos(0)?, pos(1)?);
+            let page = parse_page_arg("render", &rest)?.unwrap_or(1);
+            let scale = parse_scale_arg("render", &rest)?.unwrap_or(2.0);
             let mut s = open(&i)?;
-            let page = arg_value(&rest, "--page").and_then(|p| p.parse::<u64>().ok()).unwrap_or(1);
-            let scale = arg_value(&rest, "--scale").and_then(|p| p.parse::<f64>().ok()).unwrap_or(2.0);
             let r = s.run("file.exportPng", &json!({"path": o, "page": page, "scale": scale})).map_err(|e| e.to_string())?;
             write_stdout(|o| writeln!(o, "{r}"))
         }
         "run" => {
             validate_options("run", &rest, RUN_OPTIONS)?;
+            let page = parse_page_arg("run", &rest)?;
+            let scale = parse_scale_arg("run", &rest)?;
             let mut s = match (arg_value(&rest, "--file"), arg_value(&rest, "--template")) {
                 (Some(f), _) => open(&f)?,
                 (None, Some(t)) => {
@@ -307,10 +361,10 @@ fn run(args: &[String]) -> Result<(), Failure> {
             if let Some(out) = arg_value(&rest, "--save") {
                 let r = if out.to_ascii_lowercase().ends_with(".png") {
                     let mut v = json!({"path": out});
-                    if let Some(n) = arg_value(&rest, "--page").and_then(|p| p.parse::<u64>().ok()) {
+                    if let Some(n) = page {
                         v["page"] = json!(n);
                     }
-                    if let Some(k) = arg_value(&rest, "--scale").and_then(|p| p.parse::<f64>().ok()) {
+                    if let Some(k) = scale {
                         v["scale"] = json!(k);
                     }
                     s.run("file.exportPng", &v)
@@ -606,4 +660,173 @@ mod tests {
         let e = run(&args(&["mcp", "--connect", "127.0.0.1:9", "--automation-read-root", &dir])).unwrap_err().to_string();
         assert!(e.contains("--automation-read-root") && e.contains("headless"), "{e}");
     }
+
+    #[test]
+    fn render_rejects_missing_or_invalid_page_and_scale() {
+        // Missing operands
+        assert_eq!(run(&args(&["render", "missing.docx", "out.png", "--page"])), Err("render: --page requires a value".into()));
+        assert_eq!(run(&args(&["render", "missing.docx", "out.png", "--scale"])), Err("render: --scale requires a value".into()));
+        assert_eq!(run(&args(&["render", "missing.docx", "out.png", "--page", "--scale", "2"])), Err("render: --page requires a value".into()));
+        assert_eq!(run(&args(&["render", "missing.docx", "out.png", "--scale", "--page", "1"])), Err("render: --scale requires a value".into()));
+
+        // Non-numeric operands
+        assert_eq!(
+            run(&args(&["render", "missing.docx", "out.png", "--page", "banana"])),
+            Err("render: invalid --page `banana`: not a valid integer".into())
+        );
+        assert_eq!(
+            run(&args(&["render", "missing.docx", "out.png", "--scale", "banana"])),
+            Err("render: invalid --scale `banana`: not a number".into())
+        );
+
+        // Out-of-range values
+        assert_eq!(
+            run(&args(&["render", "missing.docx", "out.png", "--page", "0"])),
+            Err("render: invalid --page `0`: page numbers start at 1".into())
+        );
+        assert_eq!(
+            run(&args(&["render", "missing.docx", "out.png", "--page", "-1"])),
+            Err("render: invalid --page `-1`: not a valid integer".into())
+        );
+        assert_eq!(
+            run(&args(&["render", "missing.docx", "out.png", "--scale", "0"])),
+            Err("render: invalid --scale `0`: scale must be a positive number".into())
+        );
+        assert_eq!(
+            run(&args(&["render", "missing.docx", "out.png", "--scale", "-2"])),
+            Err("render: invalid --scale `-2`: scale must be a positive number".into())
+        );
+        assert_eq!(
+            run(&args(&["render", "missing.docx", "out.png", "--scale", "NaN"])),
+            Err("render: invalid --scale `NaN`: scale must be a positive number".into())
+        );
+        assert_eq!(
+            run(&args(&["render", "missing.docx", "out.png", "--scale", "inf"])),
+            Err("render: invalid --scale `inf`: scale must be a positive number".into())
+        );
+
+        // Duplicate options
+        assert_eq!(run(&args(&["render", "missing.docx", "out.png", "--page", "1", "--page", "2"])), Err("render: duplicate --page option".into()));
+        assert_eq!(
+            run(&args(&["render", "missing.docx", "out.png", "--scale", "1", "--scale", "2"])),
+            Err("render: duplicate --scale option".into())
+        );
+    }
+
+    #[test]
+    fn run_rejects_missing_or_invalid_page_and_scale() {
+        // Missing operands
+        assert_eq!(run(&args(&["run", "--template", "sample", "--save", "out.png", "--page"])), Err("run: --page requires a value".into()));
+        assert_eq!(run(&args(&["run", "--template", "sample", "--save", "out.png", "--scale"])), Err("run: --scale requires a value".into()));
+        assert_eq!(
+            run(&args(&["run", "--template", "sample", "--save", "out.png", "--page", "--scale", "2"])),
+            Err("run: --page requires a value".into())
+        );
+        assert_eq!(
+            run(&args(&["run", "--template", "sample", "--save", "out.png", "--scale", "--page", "1"])),
+            Err("run: --scale requires a value".into())
+        );
+
+        // Non-numeric operands
+        assert_eq!(
+            run(&args(&["run", "--template", "sample", "--save", "out.png", "--page", "banana"])),
+            Err("run: invalid --page `banana`: not a valid integer".into())
+        );
+        assert_eq!(
+            run(&args(&["run", "--template", "sample", "--save", "out.png", "--scale", "banana"])),
+            Err("run: invalid --scale `banana`: not a number".into())
+        );
+
+        // Out-of-range values
+        assert_eq!(
+            run(&args(&["run", "--template", "sample", "--save", "out.png", "--page", "0"])),
+            Err("run: invalid --page `0`: page numbers start at 1".into())
+        );
+        assert_eq!(
+            run(&args(&["run", "--template", "sample", "--save", "out.png", "--page", "-1"])),
+            Err("run: invalid --page `-1`: not a valid integer".into())
+        );
+        assert_eq!(
+            run(&args(&["run", "--template", "sample", "--save", "out.png", "--scale", "0"])),
+            Err("run: invalid --scale `0`: scale must be a positive number".into())
+        );
+        assert_eq!(
+            run(&args(&["run", "--template", "sample", "--save", "out.png", "--scale", "-1"])),
+            Err("run: invalid --scale `-1`: scale must be a positive number".into())
+        );
+        assert_eq!(
+            run(&args(&["run", "--template", "sample", "--save", "out.png", "--scale", "NaN"])),
+            Err("run: invalid --scale `NaN`: scale must be a positive number".into())
+        );
+        assert_eq!(
+            run(&args(&["run", "--template", "sample", "--save", "out.png", "--scale", "inf"])),
+            Err("run: invalid --scale `inf`: scale must be a positive number".into())
+        );
+
+        // Duplicate options
+        assert_eq!(
+            run(&args(&["run", "--template", "sample", "--save", "out.png", "--page", "1", "--page", "2"])),
+            Err("run: duplicate --page option".into())
+        );
+        assert_eq!(
+            run(&args(&["run", "--template", "sample", "--save", "out.png", "--scale", "1", "--scale", "2"])),
+            Err("run: duplicate --scale option".into())
+        );
+    }
+
+    #[test]
+    fn render_and_run_valid_options_and_defaults_produce_files() {
+        let dir = std::env::temp_dir().join(format!("wc-cli-render-{}", std::process::id()));
+        let _ = std::fs::remove_dir_all(&dir);
+        std::fs::create_dir_all(&dir).unwrap();
+
+        let docx_path = dir.join("sample.docx");
+        // Create sample docx via `run --save sample.docx`
+        assert!(run(&args(&["run", "--template", "sample", "--save", &docx_path.to_string_lossy()])).is_ok());
+        assert!(docx_path.exists());
+
+        let docx_str = docx_path.to_string_lossy().into_owned();
+
+        // 1. render with defaults
+        let out_default = dir.join("out_default.png");
+        assert!(run(&args(&["render", &docx_str, &out_default.to_string_lossy()])).is_ok());
+        assert!(out_default.exists());
+
+        // 2. render with valid --page and --scale
+        let out_valid = dir.join("out_valid.png");
+        assert!(run(&args(&["render", &docx_str, &out_valid.to_string_lossy(), "--page", "1", "--scale", "2"])).is_ok());
+        assert!(out_valid.exists());
+
+        // 3. render with different flag order
+        let out_reordered = dir.join("out_reordered.png");
+        assert!(run(&args(&["render", &docx_str, &out_reordered.to_string_lossy(), "--scale", "1", "--page", "1"])).is_ok());
+        assert!(out_reordered.exists());
+
+        // 4. render failure leaves no output file
+        let out_invalid = dir.join("out_invalid.png");
+        assert!(run(&args(&["render", &docx_str, &out_invalid.to_string_lossy(), "--page", "banana"])).is_err());
+        assert!(!out_invalid.exists());
+
+        // 5. run --save out.png with defaults
+        let run_default = dir.join("run_default.png");
+        assert!(run(&args(&["run", "--file", &docx_str, "--save", &run_default.to_string_lossy()])).is_ok());
+        assert!(run_default.exists());
+
+        // 6. run --save out.png with --page and --scale
+        let run_valid = dir.join("run_valid.png");
+        assert!(run(&args(&["run", "--file", &docx_str, "--save", &run_valid.to_string_lossy(), "--page", "1", "--scale", "1"])).is_ok());
+        assert!(run_valid.exists());
+
+        // 7. run --save out.png with different flag order
+        let run_reordered = dir.join("run_reordered.png");
+        assert!(run(&args(&["run", "--file", &docx_str, "--scale", "1", "--page", "1", "--save", &run_reordered.to_string_lossy()])).is_ok());
+        assert!(run_reordered.exists());
+
+        // 8. run --save out.png failure leaves no output file
+        let run_invalid = dir.join("run_invalid.png");
+        assert!(run(&args(&["run", "--file", &docx_str, "--save", &run_invalid.to_string_lossy(), "--scale", "banana"])).is_err());
+        assert!(!run_invalid.exists());
+
+        let _ = std::fs::remove_dir_all(dir);
+    }
 }