memory: delete tools report success when nothing matched #4740

delete_entities, delete_observations and delete_relations return success: true with a hardcoded message regardless of what matched.

src/memory/index.ts:

async deleteEntities(entityNames: string[]): Promise<void> {
  const graph = await this.loadGraph();
  graph.entities = graph.entities.filter(e => !entityNames.includes(e.name));

structuredContent: { success: true, message: "Entities deleted successfully" }

The method returns void, so the handler never learns whether a name existed. A call naming an entity that is not in the graph reports the same success as one that deleted something.

Reproduction, against the real KnowledgeGraphManager:

await manager.createEntities([{ name: "Alice", entityType: "person", observations: [] }]);
await callTool("delete_entities", { entityNames: ["Alise"] });
// → { success: true, message: "Entities deleted successfully" }
// Alice is still in the graph.

Same for delete_observations with an entity or observation that is absent, and delete_relations with a relation that matches nothing.

addObservations at line 167 throws Entity with name ${o.entityName} not found for the same condition, so the two paths in this file answer differently.

README.md documents the tools as silent when a target is missing, so not throwing looks intentional. The response claiming a deletion that did not occur is the part that appears unintended.