diff --git a/rust/crates/commands/src/lib.rs b/rust/crates/commands/src/lib.rs
index 4dc5f6ee..a6088f42 100644
--- a/rust/crates/commands/src/lib.rs
+++ b/rust/crates/commands/src/lib.rs
@@ -2301,12 +2301,9 @@ pub fn handle_plugins_slash_command(
                 reload_runtime: true,
             })
         }
-        Some(other) => Ok(PluginsCommandResult {
-            message: format!(
-                "Unknown /plugins action '{other}'. Use list, install, enable, disable, uninstall, or update."
-            ),
-            reload_runtime: false,
-        }),
+        Some(other) => Err(PluginError::CommandFailed(format!(
+            "unknown_plugins_action: '{other}' is not a supported /plugins action. Use list, install, enable, disable, uninstall, or update."
+        ))),
     }
 }
 
diff --git a/rust/crates/rusty-claude-cli/src/main.rs b/rust/crates/rusty-claude-cli/src/main.rs
index 50d4427f..00e2fd9c 100644
--- a/rust/crates/rusty-claude-cli/src/main.rs
+++ b/rust/crates/rusty-claude-cli/src/main.rs
@@ -308,6 +308,8 @@ fn classify_error_kind(message: &str) -> &'static str {
         "skill_not_found"
     } else if message.contains("Unsupported config section") {
         "unsupported_config_section"
+    } else if message.contains("unknown_plugins_action") {
+        "unknown_plugins_action"
     } else {
         "unknown"
     }