fix: address Dale's PR review - direct schema.get assertions, remove ArrayTool

- Replace loose schema_str.contains(...) assertions with direct
  schema.get("type") equality checks in test_tool_builder_methods.rs
  and test_structured_output.rs
- Remove redundant ArrayTool fixture and its round-trip
  serde_json::from_str test from tool_traits.rs since schema is
  already Arc<JsonObject>
- Drop dead schema_str variable in test_structured_output.rs

Author: Brandon Bennett

crates/rmcp/src/handler/server/router/tool/tool_traits.rs

@@ -340,43 +340,4 @@ mod tests {
             assert_eq!(result, ErrorData::invalid_params("invalid params", None));
         }
     }
-
-    struct ArrayTool;
-    impl ToolBase for ArrayTool {
-        type Parameter = AddParameter;
-        type Output = Vec<AddOutput>;
-        type Error = ErrorData;
-
-        fn name() -> Cow<'static, str> {
-            "array-tool".into()
-        }
-    }
-    impl SyncTool<TraitBasedToolServer> for ArrayTool {
-        fn invoke(
-            _service: &TraitBasedToolServer,
-            _param: Self::Parameter,
-        ) -> Result<Self::Output, Self::Error> {
-            Ok(vec![])
-        }
-    }
-    impl AsyncTool<TraitBasedToolServer> for ArrayTool {
-        async fn invoke(
-            _service: &TraitBasedToolServer,
-            _param: Self::Parameter,
-        ) -> Result<Self::Output, Self::Error> {
-            Ok(vec![])
-        }
-    }
-
-    #[test]
-    fn test_toolbase_output_schema_with_array_output() {
-        let schema = ArrayTool::output_schema();
-        assert!(schema.is_some());
-        let schema = schema.unwrap();
-        let schema_value: serde_json::Value = serde_json::from_str(
-            &serde_json::to_string(&*schema).expect("failed to serialize schema"),
-        )
-        .expect("failed to parse schema JSON");
-        assert_eq!(schema_value["type"], "array");
-    }
 }

crates/rmcp/tests/test_structured_output.rs

@@ -414,6 +414,5 @@ async fn test_tool_with_primitive_output_schema() {
     let schema = get_count_tool.output_schema.as_ref().unwrap();
 
     // Check that the schema contains integer type
-    let schema_str = serde_json::to_string(schema).unwrap();
-    assert!(schema_str.contains("integer"));
+    assert_eq!(schema.get("type"), Some(&serde_json::json!("integer")));
 }

crates/rmcp/tests/test_tool_builder_methods.rs

@@ -68,10 +68,10 @@ fn test_with_output_schema_primitive() {
 
     assert!(tool.output_schema.is_some());
 
-    let schema_str = serde_json::to_string(tool.output_schema.as_ref().unwrap()).unwrap();
-    assert!(schema_str.contains("\"type\":\"integer\""));
+    let schema = tool.output_schema.as_ref().unwrap();
+    assert_eq!(schema.get("type"), Some(&serde_json::json!("integer")));
     // title should be stripped from output schema
-    assert!(!schema_str.contains("title"));
+    assert!(schema.get("title").is_none());
 }
 
 #[test]