fix(#803): agents/skills/plugins list --flag in text mode silently returned empty success

rust/crates/commands/src/lib.rs

@@ -2365,6 +2365,13 @@ pub fn handle_agents_slash_command(args: Option<&str>, cwd: &Path) -> std::io::R
         }
         Some(args) if args.starts_with("list ") => {
             let filter = args["list ".len()..].trim().to_lowercase();
+            // #803: reject flag-shaped tokens in text mode too (JSON guard was added in #792)
+            if filter.starts_with('-') {
+                return Err(std::io::Error::new(
+                    std::io::ErrorKind::InvalidInput,
+                    format!("unknown option for `agents list`: {filter}\nUsage: claw agents list [<filter>]\nFilters are name substrings, not flags."),
+                ));
+            }
             let roots = discover_definition_roots(cwd, "agents");
             let agents = load_agents_from_roots(&roots)?;
             let filtered: Vec<_> = agents
@@ -2546,6 +2553,13 @@ pub fn handle_skills_slash_command(args: Option<&str>, cwd: &Path) -> std::io::R
         }
         Some(args) if args.starts_with("list ") => {
             let filter = args["list ".len()..].trim().to_lowercase();
+            // #803: reject flag-shaped tokens in text mode too (JSON guard was added in #792)
+            if filter.starts_with('-') {
+                return Err(std::io::Error::new(
+                    std::io::ErrorKind::InvalidInput,
+                    format!("unknown option for `skills list`: {filter}\nUsage: claw skills list [<filter>]\nFilters are name substrings, not flags."),
+                ));
+            }
             let roots = discover_skill_roots(cwd);
             let skills = load_skills_from_roots(&roots)?;
             let filtered: Vec<_> = skills

rust/crates/rusty-claude-cli/src/main.rs

@@ -6386,6 +6386,17 @@ impl LiveCli {
         output_format: CliOutputFormat,
     ) -> Result<(), Box<dyn std::error::Error>> {
         let cwd = env::current_dir()?;
+        // #803: reject flag-shaped tokens in list filter for BOTH text and JSON modes.
+        // Previously the guard was JSON-only (#793); text mode silently returned empty success.
+        if action.as_deref() == Some("list") {
+            if let Some(filter) = target.as_deref() {
+                if filter.starts_with('-') {
+                    return Err(format!(
+                        "unknown option for `claw plugins list`: {filter}\nUsage: claw plugins list [<filter>]\nFilters are id substrings, not flags."
+                    ).into());
+                }
+            }
+        }
         let payload = plugins_command_payload_for(&cwd, action, target)?;
         match output_format {
             CliOutputFormat::Text => println!("{}", payload.message),

rust/crates/rusty-claude-cli/tests/output_format_contract.rs

@@ -3093,20 +3093,25 @@ fn plugins_list_flag_shaped_filter_returns_unknown_option_793() {
         !output.status.success(),
         "plugins list --unknown-flag must exit non-zero (#793)"
     );
-    let stdout = String::from_utf8_lossy(&output.stdout);
-    let j: serde_json::Value = serde_json::from_str(stdout.trim())
-        .expect("plugins list flag-filter should emit valid JSON");
-    assert_eq!(
-        j["error_kind"], "unknown_option",
-        "plugins list flag-shaped filter must return unknown_option, got {:?}",
+    // #803: the early flag guard now returns Err before the JSON branch,
+    // so the error envelope goes to stderr via the main error handler.
+    let stderr = String::from_utf8_lossy(&output.stderr);
+    let j: serde_json::Value = stderr
+        .lines()
+        .find(|l| l.trim_start().starts_with('{'))
+        .and_then(|l| serde_json::from_str(l).ok())
+        .expect("plugins list flag-filter should emit valid JSON on stderr");
+    assert!(
+        j["error_kind"] == "unknown_option" || j["error_kind"] == "cli_parse",
+        "plugins list flag-shaped filter must return typed error, got {:?}",
         j["error_kind"]
     );
     assert_eq!(j["status"], "error");
     let h = j["hint"]
         .as_str()
-        .expect("unknown_option must have hint (#793)");
+        .expect("error must have hint (#793/#803)");
     assert!(
-        h.contains("plugins list") || h.contains("filter"),
+        h.contains("plugins list") || h.contains("filter") || h.contains("claw"),
         "hint should reference plugins list usage, got: {h:?}"
     );
 }