From 1ae29199967a143d140968f1a8343feb685c1abc Mon Sep 17 00:00:00 2001
From: Michael Neale <michael.neale@gmail.com>
Date: Thu, 7 Aug 2025 10:29:02 +1000
Subject: [PATCH 1/2] allow backwards compat as per MCP spec

---
 crates/rmcp/src/model.rs                    |  3 +--
 crates/rmcp/tests/test_structured_output.rs | 21 ---------------------
 2 files changed, 1 insertion(+), 23 deletions(-)

diff --git a/crates/rmcp/src/model.rs b/crates/rmcp/src/model.rs
index f0c92c0a..56e484b1 100644
--- a/crates/rmcp/src/model.rs
+++ b/crates/rmcp/src/model.rs
@@ -1262,10 +1262,9 @@ impl CallToolResult {
         }
     }
 
-    /// Validate that content and structured_content are mutually exclusive
+    /// Validate that content or structured content is provided
     pub fn validate(&self) -> Result<(), &'static str> {
         match (&self.content, &self.structured_content) {
-            (Some(_), Some(_)) => Err("content and structured_content are mutually exclusive"),
             (None, None) => Err("either content or structured_content must be provided"),
             _ => Ok(()),
         }
diff --git a/crates/rmcp/tests/test_structured_output.rs b/crates/rmcp/tests/test_structured_output.rs
index 7e85d0e7..92aa27f9 100644
--- a/crates/rmcp/tests/test_structured_output.rs
+++ b/crates/rmcp/tests/test_structured_output.rs
@@ -144,27 +144,6 @@ async fn test_structured_error_in_call_result() {
     assert_eq!(result.is_error, Some(true));
 }
 
-#[tokio::test]
-async fn test_mutual_exclusivity_validation() {
-    // Test that content and structured_content are mutually exclusive
-    let content_result = CallToolResult::success(vec![Content::text("Hello")]);
-    let structured_result = CallToolResult::structured(json!({"message": "Hello"}));
-
-    // Verify the validation
-    assert!(content_result.validate().is_ok());
-    assert!(structured_result.validate().is_ok());
-
-    // Try to create an invalid result with both fields
-    let invalid_json = json!({
-        "content": [{"type": "text", "text": "Hello"}],
-        "structuredContent": {"message": "Hello"}
-    });
-
-    // The deserialization itself should fail due to validation
-    let deserialized: Result<CallToolResult, _> = serde_json::from_value(invalid_json);
-    assert!(deserialized.is_err());
-}
-
 #[tokio::test]
 async fn test_structured_return_conversion() {
     // Test that Json<T> converts to CallToolResult with structured_content

From 7f33cdf13ce1812decd3666f61d40b7cbe92610a Mon Sep 17 00:00:00 2001
From: Michael Neale <michael.neale@gmail.com>
Date: Thu, 7 Aug 2025 13:42:39 +1000
Subject: [PATCH 2/2] fix(model): remove unneeded import

---
 crates/rmcp/tests/test_structured_output.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crates/rmcp/tests/test_structured_output.rs b/crates/rmcp/tests/test_structured_output.rs
index 92aa27f9..8b6cb0cb 100644
--- a/crates/rmcp/tests/test_structured_output.rs
+++ b/crates/rmcp/tests/test_structured_output.rs
@@ -2,7 +2,7 @@
 use rmcp::{
     Json, ServerHandler,
     handler::server::{router::tool::ToolRouter, tool::Parameters},
-    model::{CallToolResult, Content, Tool},
+    model::{CallToolResult, Tool},
     tool, tool_handler, tool_router,
 };
 use schemars::JsonSchema;