diff --git a/crates/zeph-core/src/agent/mod.rs b/crates/zeph-core/src/agent/mod.rs
index 93905c17..dff9ee47 100644
--- a/crates/zeph-core/src/agent/mod.rs
+++ b/crates/zeph-core/src/agent/mod.rs
@@ -1159,6 +1159,7 @@ pub(super) mod agent_tests {
             blocks_executed: 1,
             filter_stats: None,
             diff: None,
+            streamed: false,
         }))]);
 
         let agent_channel = MockChannel::new(vec!["execute tool".to_string()]);
@@ -1358,6 +1359,7 @@ pub(super) mod agent_tests {
                 blocks_executed: 1,
                 filter_stats: None,
                 diff: None,
+                streamed: false,
             })),
             Ok(None),
         ]);
@@ -1379,6 +1381,7 @@ pub(super) mod agent_tests {
             blocks_executed: 1,
             filter_stats: None,
             diff: None,
+            streamed: false,
         }))]);
 
         let mut agent = Agent::new(provider, channel, registry, None, 5, executor);
@@ -1472,6 +1475,7 @@ pub(super) mod agent_tests {
                 blocks_executed: 1,
                 filter_stats: None,
                 diff: None,
+                streamed: false,
             })),
             Ok(None),
         ]);
@@ -1501,6 +1505,7 @@ pub(super) mod agent_tests {
                 blocks_executed: 1,
                 filter_stats: None,
                 diff: None,
+                streamed: false,
             })));
         }
         let executor = MockToolExecutor::new(outputs);
diff --git a/crates/zeph-core/src/agent/streaming.rs b/crates/zeph-core/src/agent/streaming.rs
index eecf2855..87497312 100644
--- a/crates/zeph-core/src/agent/streaming.rs
+++ b/crates/zeph-core/src/agent/streaming.rs
@@ -661,7 +661,7 @@ impl<C: Channel, T: ToolExecutor> Agent<C, T> {
         // Process results sequentially (metrics, channel sends, message parts)
         let mut result_parts: Vec<MessagePart> = Vec::new();
         for (tc, tool_result) in tool_calls.iter().zip(tool_results) {
-            let (output, is_error, diff, inline_stats) = match tool_result {
+            let (output, is_error, diff, inline_stats, already_streamed) = match tool_result {
                 Ok(Some(out)) => {
                     if let Some(ref fs) = out.filter_stats {
                         let saved = fs.estimated_tokens_saved() as u64;
@@ -694,10 +694,11 @@ impl<C: Channel, T: ToolExecutor> Agent<C, T> {
                     let inline_stats = out.filter_stats.as_ref().and_then(|fs| {
                         (fs.filtered_chars < fs.raw_chars).then(|| fs.format_inline(&tc.name))
                     });
-                    (out.summary, false, out.diff, inline_stats)
+                    let streamed = out.streamed;
+                    (out.summary, false, out.diff, inline_stats, streamed)
                 }
-                Ok(None) => ("(no output)".to_owned(), false, None, None),
-                Err(e) => (format!("[error] {e}"), true, None, None),
+                Ok(None) => ("(no output)".to_owned(), false, None, None, false),
+                Err(e) => (format!("[error] {e}"), true, None, None, false),
             };
 
             let processed = self.maybe_summarize_tool_output(&output).await;
@@ -708,18 +709,13 @@ impl<C: Channel, T: ToolExecutor> Agent<C, T> {
             };
             let formatted = format_tool_output(&tc.name, &body);
             let display = self.maybe_redact(&formatted);
-            // Bundle diff and filter stats into a single atomic send so TUI can attach
-            // them to the tool message without a race between DiffReady and FullMessage.
-            let disp_len = display.len();
-            tracing::debug!(
-                tool_name = %tc.name,
-                has_diff = diff.is_some(),
-                disp_len,
-                "about to call send_tool_output"
-            );
-            self.channel
-                .send_tool_output(&tc.name, &display, diff, inline_stats)
-                .await?;
+            // Tools that already streamed via ToolEvent channel (e.g. bash) have their
+            // output displayed by the TUI event forwarder; skip duplicate send.
+            if !already_streamed {
+                self.channel
+                    .send_tool_output(&tc.name, &display, diff, inline_stats)
+                    .await?;
+            }
 
             result_parts.push(MessagePart::ToolResult {
                 tool_use_id: tc.id.clone(),
@@ -808,6 +804,7 @@ mod tests {
                     blocks_executed: 1,
                     diff: None,
                     filter_stats: None,
+                    streamed: false,
                 }))
             }
         }
@@ -846,6 +843,7 @@ mod tests {
                         blocks_executed: 1,
                         diff: None,
                         filter_stats: None,
+                        streamed: false,
                     }))
                 }
             }
diff --git a/crates/zeph-mcp/src/executor.rs b/crates/zeph-mcp/src/executor.rs
index 9caab457..e6e331b8 100644
--- a/crates/zeph-mcp/src/executor.rs
+++ b/crates/zeph-mcp/src/executor.rs
@@ -69,6 +69,7 @@ impl ToolExecutor for McpToolExecutor {
             blocks_executed,
             filter_stats: None,
             diff: None,
+            streamed: false,
         }))
     }
 }
diff --git a/crates/zeph-tools/src/composite.rs b/crates/zeph-tools/src/composite.rs
index 0621bf25..217e8621 100644
--- a/crates/zeph-tools/src/composite.rs
+++ b/crates/zeph-tools/src/composite.rs
@@ -61,6 +61,7 @@ mod tests {
                 blocks_executed: 1,
                 filter_stats: None,
                 diff: None,
+                streamed: false,
             }))
         }
     }
@@ -93,6 +94,7 @@ mod tests {
                 blocks_executed: 1,
                 filter_stats: None,
                 diff: None,
+                streamed: false,
             }))
         }
     }
@@ -170,6 +172,7 @@ mod tests {
                     blocks_executed: 1,
                     filter_stats: None,
                     diff: None,
+                    streamed: false,
                 }))
             } else {
                 Ok(None)
@@ -194,6 +197,7 @@ mod tests {
                     blocks_executed: 1,
                     filter_stats: None,
                     diff: None,
+                    streamed: false,
                 }))
             } else {
                 Ok(None)
diff --git a/crates/zeph-tools/src/executor.rs b/crates/zeph-tools/src/executor.rs
index fd52f819..ba7f1d69 100644
--- a/crates/zeph-tools/src/executor.rs
+++ b/crates/zeph-tools/src/executor.rs
@@ -73,6 +73,8 @@ pub struct ToolOutput {
     pub blocks_executed: u32,
     pub filter_stats: Option<FilterStats>,
     pub diff: Option<DiffData>,
+    /// Whether this tool already streamed its output via `ToolEvent` channel.
+    pub streamed: bool,
 }
 
 impl fmt::Display for ToolOutput {
@@ -213,6 +215,7 @@ mod tests {
             blocks_executed: 1,
             filter_stats: None,
             diff: None,
+            streamed: false,
         };
         assert_eq!(output.to_string(), "$ echo hello\nhello");
     }
diff --git a/crates/zeph-tools/src/file.rs b/crates/zeph-tools/src/file.rs
index fb99ec01..0e492245 100644
--- a/crates/zeph-tools/src/file.rs
+++ b/crates/zeph-tools/src/file.rs
@@ -145,6 +145,7 @@ impl FileExecutor {
             blocks_executed: 1,
             filter_stats: None,
             diff: None,
+            streamed: false,
         }))
     }
 
@@ -173,6 +174,7 @@ impl FileExecutor {
                 old_content,
                 new_content: content,
             }),
+            streamed: false,
         }))
     }
 
@@ -206,6 +208,7 @@ impl FileExecutor {
                 old_content: content,
                 new_content,
             }),
+            streamed: false,
         }))
     }
 
@@ -239,6 +242,7 @@ impl FileExecutor {
             blocks_executed: 1,
             filter_stats: None,
             diff: None,
+            streamed: false,
         }))
     }
 
@@ -282,6 +286,7 @@ impl FileExecutor {
             blocks_executed: 1,
             filter_stats: None,
             diff: None,
+            streamed: false,
         }))
     }
 }
diff --git a/crates/zeph-tools/src/scrape.rs b/crates/zeph-tools/src/scrape.rs
index 7354e3be..ab852389 100644
--- a/crates/zeph-tools/src/scrape.rs
+++ b/crates/zeph-tools/src/scrape.rs
@@ -107,6 +107,7 @@ impl ToolExecutor for WebScrapeExecutor {
             blocks_executed,
             filter_stats: None,
             diff: None,
+            streamed: false,
         }))
     }
 
@@ -136,6 +137,7 @@ impl ToolExecutor for WebScrapeExecutor {
             blocks_executed: 1,
             filter_stats: None,
             diff: None,
+            streamed: false,
         }))
     }
 }
diff --git a/crates/zeph-tools/src/shell.rs b/crates/zeph-tools/src/shell.rs
index 3d4f807e..89c09fed 100644
--- a/crates/zeph-tools/src/shell.rs
+++ b/crates/zeph-tools/src/shell.rs
@@ -268,6 +268,7 @@ impl ShellExecutor {
             blocks_executed,
             filter_stats: cumulative_filter_stats,
             diff: None,
+            streamed: self.tool_event_tx.is_some(),
         }))
     }
 
diff --git a/crates/zeph-tools/src/trust_gate.rs b/crates/zeph-tools/src/trust_gate.rs
index 6674cb7e..e9d1f7bc 100644
--- a/crates/zeph-tools/src/trust_gate.rs
+++ b/crates/zeph-tools/src/trust_gate.rs
@@ -120,6 +120,7 @@ mod tests {
                 blocks_executed: 1,
                 filter_stats: None,
                 diff: None,
+                streamed: false,
             }))
         }
     }
diff --git a/tests/integration.rs b/tests/integration.rs
index 9fec248b..fb30d090 100644
--- a/tests/integration.rs
+++ b/tests/integration.rs
@@ -167,6 +167,7 @@ impl ToolExecutor for OutputToolExecutor {
             blocks_executed: 1,
             filter_stats: None,
             diff: None,
+            streamed: false,
         }))
     }
 }
@@ -181,6 +182,7 @@ impl ToolExecutor for EmptyOutputToolExecutor {
             blocks_executed: 1,
             filter_stats: None,
             diff: None,
+            streamed: false,
         }))
     }
 }
@@ -195,6 +197,7 @@ impl ToolExecutor for ErrorOutputToolExecutor {
             blocks_executed: 1,
             filter_stats: None,
             diff: None,
+            streamed: false,
         }))
     }
 }
@@ -225,6 +228,7 @@ impl ToolExecutor for ConfirmToolExecutor {
             blocks_executed: 1,
             filter_stats: None,
             diff: None,
+            streamed: false,
         }))
     }
 }
@@ -260,6 +264,7 @@ impl ToolExecutor for ExitCodeToolExecutor {
             blocks_executed: 1,
             filter_stats: None,
             diff: None,
+            streamed: false,
         }))
     }
 }
@@ -2167,6 +2172,7 @@ mod self_learning {
                 blocks_executed: 1,
                 filter_stats: None,
                 diff: None,
+                streamed: false,
             }))
         }
     }
diff --git a/tests/performance_agent_integration.rs b/tests/performance_agent_integration.rs
index 6417c930..0823def8 100644
--- a/tests/performance_agent_integration.rs
+++ b/tests/performance_agent_integration.rs
@@ -102,6 +102,7 @@ impl ToolExecutor for InstrumentedMockExecutor {
                 blocks_executed: 1,
                 filter_stats: None,
                 diff: None,
+                streamed: false,
             }))
         } else {
             Ok(None)