fix: widen MOIM allowlist to apply fix_conversation repairs for orphaned tool blocks

Production death loop: after tool-heavy responses, orphaned tool_use/tool_result
blocks cause persistent Anthropic API 400 errors. fix_conversation correctly
detects and repairs these orphans, but MOIM's allowlist only permitted merge
operations. Any other fix — including orphan removal — caused MOIM to discard
the repair and return the original broken conversation to the provider.

Widens the allowlist to also accept orphan removal, empty message cleanup,
leading/trailing assistant removal, and text content merging. These are all
legitimate repairs that fix_conversation should be allowed to apply regardless
of whether MOIM insertion triggered the detection.

Author: wpfleger96

crates/goose/src/agents/moim.rs

@@ -35,6 +35,12 @@ pub async fn inject_moim(
         let has_unexpected_issues = issues.iter().any(|issue| {
             !issue.contains("Merged consecutive user messages")
                 && !issue.contains("Merged consecutive assistant messages")
+                && !issue.contains("Merged text content")
+                && !issue.contains("Removed orphaned tool response")
+                && !issue.contains("Removed orphaned tool request")
+                && !issue.contains("Removed empty message")
+                && !issue.contains("Removed leading assistant message")
+                && !issue.contains("Removed trailing assistant message")
         });
 
         if has_unexpected_issues {
@@ -170,4 +176,130 @@ mod tests {
             "MOIM should be in message before latest assistant message"
         );
     }
+
+    // After the allowlist fix: MOIM now applies the fix when fix_conversation detects an
+    // orphaned tool request, removing it from the conversation.
+    #[tokio::test]
+    async fn test_moim_fixes_orphaned_tool_request() {
+        let temp_dir = tempfile::tempdir().unwrap();
+        let em = ExtensionManager::new_without_provider(temp_dir.path().to_path_buf());
+        let working_dir = PathBuf::from("/test/dir");
+
+        let broken_conv = Conversation::new_unvalidated(vec![
+            Message::user().with_text("Do something"),
+            Message::assistant()
+                .with_text("I'll call a tool")
+                .with_tool_request(
+                    "orphan_tool_1",
+                    Ok(CallToolRequestParams {
+                        meta: None,
+                        task: None,
+                        name: "some_tool".into(),
+                        arguments: None,
+                    }),
+                ),
+        ]);
+
+        // Control: fix_conversation alone correctly removes the orphaned tool request.
+        let (_, issues) = fix_conversation(Conversation::new_unvalidated(
+            broken_conv.messages().clone(),
+        ));
+        assert!(
+            issues
+                .iter()
+                .any(|i| i.contains("Removed orphaned tool request")),
+            "fix_conversation alone should detect the orphan, but issues were: {:?}",
+            issues
+        );
+
+        // inject_moim now applies the fix (orphan removal is in the allowlist).
+        let result = inject_moim("test-session-id", broken_conv.clone(), &em, &working_dir).await;
+        let msgs = result.messages();
+
+        // The orphaned ToolRequest should be removed.
+        let has_orphan = msgs.iter().any(|m| {
+            m.content.iter().any(|c| {
+                matches!(c, crate::conversation::message::MessageContent::ToolRequest(tr) if tr.id == "orphan_tool_1")
+            })
+        });
+        assert!(
+            !has_orphan,
+            "Orphaned tool request should have been removed by MOIM's fix_conversation"
+        );
+
+        // MOIM should have been injected (conversation was fixed).
+        let has_moim = msgs.iter().any(|m| {
+            m.content
+                .iter()
+                .any(|c| c.as_text().is_some_and(|t| t.contains("<info-msg>")))
+        });
+        assert!(
+            has_moim,
+            "MOIM should have been injected after fixing the orphan"
+        );
+    }
+
+    // After the allowlist fix: MOIM now fixes the cancellation scenario — removes the
+    // orphaned tool request and empty user message, preventing the Anthropic 400 error.
+    #[tokio::test]
+    async fn test_moim_fixes_cancellation_orphan() {
+        let temp_dir = tempfile::tempdir().unwrap();
+        let em = ExtensionManager::new_without_provider(temp_dir.path().to_path_buf());
+        let working_dir = PathBuf::from("/test/dir");
+
+        // Simulates what the agent produces after cancellation:
+        // - Valid prior exchange
+        // - Assistant issues a tool call
+        // - Pre-allocated user message was never populated (cancellation fired first)
+        let broken_conv = Conversation::new_unvalidated(vec![
+            Message::user().with_text("Search for something"),
+            Message::assistant().with_text("I searched and found results"),
+            Message::user().with_text("Now do something else"),
+            Message::assistant()
+                .with_text("I'll call a tool")
+                .with_tool_request(
+                    "cancelled_tool",
+                    Ok(CallToolRequestParams {
+                        meta: None,
+                        task: None,
+                        name: "some_tool".into(),
+                        arguments: None,
+                    }),
+                ),
+            // Pre-allocated Message::user() never populated due to cancellation.
+            Message::user(),
+        ]);
+
+        let result = inject_moim("test-session-id", broken_conv.clone(), &em, &working_dir).await;
+        let msgs = result.messages();
+
+        // The orphaned ToolRequest should be removed.
+        let has_orphan = msgs.iter().any(|m| {
+            m.content.iter().any(|c| {
+                matches!(c, crate::conversation::message::MessageContent::ToolRequest(tr) if tr.id == "cancelled_tool")
+            })
+        });
+        assert!(
+            !has_orphan,
+            "Orphaned tool request should have been removed by MOIM's fix_conversation"
+        );
+
+        // The empty user message should be removed.
+        let has_empty = msgs.iter().any(|m| m.content.is_empty());
+        assert!(
+            !has_empty,
+            "Empty user message should have been removed by MOIM's fix_conversation"
+        );
+
+        // MOIM should have been injected.
+        let has_moim = msgs.iter().any(|m| {
+            m.content
+                .iter()
+                .any(|c| c.as_text().is_some_and(|t| t.contains("<info-msg>")))
+        });
+        assert!(
+            has_moim,
+            "MOIM should have been injected after fixing the cancellation orphan"
+        );
+    }
 }

crates/goose/src/context_mgmt/mod.rs

@@ -825,4 +825,121 @@ mod tests {
         let result = tool_id_to_summarize(&updated_conversation, 3);
         assert!(result.is_none(), "Nothing left to summarize");
     }
+
+    // Control test: after compaction + appending new tool calls, fix_conversation
+    // produces zero issues. Proves compaction output is structurally clean and
+    // compatible with the fix pipeline when new tool pairs are added.
+    #[tokio::test]
+    async fn test_compaction_output_with_new_tool_pair_is_valid() {
+        let response_message = Message::assistant().with_text("<mock summary>");
+        let provider = MockProvider::new(response_message, 1000);
+
+        // Pre-compaction conversation: user text, 3 tool pairs, user text at end
+        let mut messages = vec![Message::user().with_text("Help me with a task")];
+        for i in 0..3 {
+            messages.push(Message::assistant().with_tool_request(
+                format!("old_tool_{}", i),
+                Ok(CallToolRequestParams {
+                    meta: None,
+                    task: None,
+                    name: "some_tool".into(),
+                    arguments: None,
+                }),
+            ));
+            messages.push(Message::user().with_tool_response(
+                format!("old_tool_{}", i),
+                Ok(rmcp::model::CallToolResult {
+                    content: vec![RawContent::text(format!("result {}", i)).no_annotation()],
+                    structured_content: None,
+                    is_error: Some(false),
+                    meta: None,
+                }),
+            ));
+        }
+        messages.push(Message::user().with_text("Now do something else"));
+
+        let conversation = Conversation::new_unvalidated(messages);
+        let (compacted, _usage) =
+            compact_messages(&provider, "test-session-id", &conversation, false)
+                .await
+                .unwrap();
+
+        // Simulate post-compaction agent loop: LLM makes a new tool call, tool executes
+        let new_asst = Message::assistant()
+            .with_text("I'll run a new tool")
+            .with_tool_request(
+                "new_tool_1",
+                Ok(CallToolRequestParams {
+                    meta: None,
+                    task: None,
+                    name: "new_tool".into(),
+                    arguments: None,
+                }),
+            );
+        let new_tool_resp = Message::user().with_tool_response(
+            "new_tool_1",
+            Ok(rmcp::model::CallToolResult {
+                content: vec![RawContent::text("new result").no_annotation()],
+                structured_content: None,
+                is_error: Some(false),
+                meta: None,
+            }),
+        );
+        // Rebuild conversation from compacted messages + new tool pair.
+        // Can't use Conversation::push() because it merges by ID, and we need
+        // the messages to be separate entries.
+        let mut all_msgs = compacted.messages().clone();
+        all_msgs.push(new_asst);
+        all_msgs.push(new_tool_resp);
+        let compacted = Conversation::new_unvalidated(all_msgs);
+
+        // fix_conversation should produce zero issues — the conversation is valid
+        let (fixed, issues) = crate::conversation::fix_conversation(compacted.clone());
+
+        assert!(
+            issues.is_empty(),
+            "Compacted conversation + new tool pair should have no issues, but found: {:?}",
+            issues
+        );
+
+        // The new tool pair should be intact in the visible messages
+        let visible = fixed.agent_visible_messages();
+        let has_new_tool_request = visible.iter().any(|m| {
+            m.content
+                .iter()
+                .any(|c| matches!(c, MessageContent::ToolRequest(tr) if tr.id == "new_tool_1"))
+        });
+        let has_new_tool_response = visible.iter().any(|m| {
+            m.content
+                .iter()
+                .any(|c| matches!(c, MessageContent::ToolResponse(tr) if tr.id == "new_tool_1"))
+        });
+        assert!(
+            has_new_tool_request,
+            "New tool request should be in visible messages"
+        );
+        assert!(
+            has_new_tool_response,
+            "New tool response should be in visible messages"
+        );
+
+        // The old tool pairs should still exist as non-visible messages
+        let all_msgs = fixed.messages();
+        let non_visible_tool_count = all_msgs
+            .iter()
+            .filter(|m| {
+                !m.metadata.agent_visible
+                    && m.content.iter().any(|c| {
+                        matches!(
+                            c,
+                            MessageContent::ToolRequest(_) | MessageContent::ToolResponse(_)
+                        )
+                    })
+            })
+            .count();
+        assert!(
+            non_visible_tool_count > 0,
+            "Old tool pairs should be preserved as non-visible messages"
+        );
+    }
 }