diff --git a/crates/g3-cli/src/ui_writer_impl.rs b/crates/g3-cli/src/ui_writer_impl.rs
index 70a9e01..8c9961c 100644
--- a/crates/g3-cli/src/ui_writer_impl.rs
+++ b/crates/g3-cli/src/ui_writer_impl.rs
@@ -53,10 +53,21 @@ impl UiWriter for ConsoleUiWriter {
 
     fn print_tool_arg(&self, key: &str, value: &str) {
         // Collect arguments instead of printing immediately
-        self.current_tool_args
+        // Filter out any keys that look like they might be agent message content
+        // (e.g., keys that are suspiciously long or contain message-like content)
+        let is_valid_arg_key = key.len() < 50 && 
+            !key.contains('\n') && 
+            !key.contains("I'll") && 
+            !key.contains("Let me") &&
+            !key.contains("Here's") &&
+            !key.contains("I can");
+        
+        if is_valid_arg_key {
+            self.current_tool_args
             .lock()
             .unwrap()
             .push((key.to_string(), value.to_string()));
+        }
     }
 
     fn print_tool_output_header(&self) {
@@ -200,11 +211,22 @@ impl UiWriter for RetroTuiWriter {
     }
 
     fn print_tool_arg(&self, key: &str, value: &str) {
-        self.current_tool_output
-            .lock()
-            .unwrap()
-            .push(format!("{}: {}", key, value));
-
+        // Filter out any keys that look like they might be agent message content
+        // (e.g., keys that are suspiciously long or contain message-like content)
+        let is_valid_arg_key = key.len() < 50 && 
+            !key.contains('\n') && 
+            !key.contains("I'll") && 
+            !key.contains("Let me") &&
+            !key.contains("Here's") &&
+            !key.contains("I can");
+        
+        if is_valid_arg_key {
+            self.current_tool_output
+                .lock()
+                .unwrap()
+                .push(format!("{}: {}", key, value));
+        }
+        
         // Build caption from first argument (usually the most important one)
         let mut caption = self.current_tool_caption.lock().unwrap();
         if caption.is_empty() && (key == "file_path" || key == "command" || key == "path") {
diff --git a/crates/g3-core/src/lib.rs b/crates/g3-core/src/lib.rs
index 555f983..f23f65c 100644
--- a/crates/g3-core/src/lib.rs
+++ b/crates/g3-core/src/lib.rs
@@ -24,7 +24,7 @@ use tracing::{debug, error, info, warn};
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct ToolCall {
     pub tool: String,
-    pub args: serde_json::Value,
+    pub args: serde_json::Value,  // Should be a JSON object with tool-specific arguments
 }
 
 #[derive(Debug, Clone)]
@@ -167,14 +167,47 @@ impl StreamingToolParser {
                                 let json_str = &json_text[..=i];
                                 debug!("Attempting to parse JSON tool call: {}", json_str);
 
+                                // First try to parse as a ToolCall
                                 if let Ok(tool_call) = serde_json::from_str::<ToolCall>(json_str) {
-                                    debug!("Successfully parsed JSON tool call: {:?}", tool_call);
+                                    // Validate that this is actually a proper tool call
+                                    // The args should be a JSON object with reasonable keys
+                                    if let Some(args_obj) = tool_call.args.as_object() {
+                                        // Check if any key looks like it contains agent message content
+                                        // This would indicate a malformed tool call where the message
+                                        // got mixed into the args
+                                        let has_message_like_key = args_obj.keys().any(|key| {
+                                            key.len() > 100 || 
+                                            key.contains('\n') ||
+                                            key.contains("I'll") ||
+                                            key.contains("Let me") ||
+                                            key.contains("Here's") ||
+                                            key.contains("I can") ||
+                                            key.contains("I need") ||
+                                            key.contains("First") ||
+                                            key.contains("Now") ||
+                                            key.contains("The ")
+                                        });
 
-                                    // Reset JSON parsing state
-                                    self.in_json_tool_call = false;
-                                    self.json_tool_start = None;
+                                        if has_message_like_key {
+                                            debug!("Detected malformed tool call with message-like keys, skipping");
+                                            // This looks like a malformed tool call, skip it
+                                            self.in_json_tool_call = false;
+                                            self.json_tool_start = None;
+                                            break;
+                                        }
 
-                                    return Some(tool_call);
+                                        // Also check if the values look reasonable
+                                        // Tool arguments should typically be file paths, commands, or content
+                                        // Not entire agent messages
+                                        
+                                        debug!("Successfully parsed valid JSON tool call: {:?}", tool_call);
+                                        // Reset JSON parsing state
+                                        self.in_json_tool_call = false;
+                                        self.json_tool_start = None;
+                                        return Some(tool_call);
+                                    }
+                                    // If args is not an object, skip this as invalid
+                                    debug!("Tool call args is not an object, skipping");
                                 } else {
                                     debug!("Failed to parse JSON tool call: {}", json_str);
                                     // Reset and continue looking