fix: agent usability improvements - unified schema casing, fixed silent handler failures, and made namespaces strictly optional

server/src/handlers/graph.rs

@@ -152,13 +152,25 @@ impl McpTool for CreateRelationsHandler {
 
     async fn execute(&self, args: Value, state: Arc<MemoryState>) -> Result<String, String> {
         let req: CreateRelationsTool = serde_json::from_value(args).map_err(|e| e.to_string())?;
+        let mut missing_nodes = std::collections::HashSet::new();
         state.modify_graph(|g| {
             for relation in req.relations {
                 if !relation.from.is_empty() && !relation.to.is_empty() {
-                    g.relations.push(relation);
+                    let from_exists = g.entities.contains_key(&relation.from);
+                    let to_exists = g.entities.contains_key(&relation.to);
+                    if from_exists && to_exists {
+                        g.relations.push(relation);
+                    } else {
+                        if !from_exists { missing_nodes.insert(relation.from); }
+                        if !to_exists { missing_nodes.insert(relation.to); }
+                    }
                 }
             }
         });
+        if !missing_nodes.is_empty() {
+            let missing: Vec<_> = missing_nodes.into_iter().collect();
+            return Ok(format!("Warning: Relations dropped due to missing entities: {}", missing.join(", ")));
+        }
         Ok("Relations created".to_string())
     }
 }
@@ -177,13 +189,19 @@ impl McpTool for AddObservationsHandler {
 
     async fn execute(&self, args: Value, state: Arc<MemoryState>) -> Result<String, String> {
         let req: AddObservationsTool = serde_json::from_value(args).map_err(|e| e.to_string())?;
+        let mut missing_entities = Vec::new();
         state.modify_graph(|g| {
             for o in req.observations {
                 if let Some(e) = g.entities.get_mut(&o.entity_name) {
                     e.observations.extend(o.contents);
+                } else {
+                    missing_entities.push(o.entity_name);
                 }
             }
         });
+        if !missing_entities.is_empty() {
+            return Ok(format!("Warning: Observations dropped for missing entities: {}", missing_entities.join(", ")));
+        }
         Ok("Observations added".to_string())
     }
 }