feat(memory): add tool annotations to all knowledge graph tools (#3874)

Add MCP ToolAnnotations to all 9 tools in the memory server, matching
the annotation coverage already present in server-filesystem, server-git,
server-time, and server-sequential-thinking.

- Read tools (read_graph, search_nodes, open_nodes): read-only, idempotent
- Write tools (create_entities, create_relations, add_observations): non-destructive
- Delete tools (delete_entities, delete_observations, delete_relations): destructive, idempotent
- All tools: openWorldHint=false (local JSONL file operations only)

Co-authored-by: Ola Hungerford <olahungerford@gmail.com>

src/memory/index.ts

@@ -269,6 +269,12 @@ server.registerTool(
     },
     outputSchema: {
       entities: z.array(EntitySchema)
+    },
+    annotations: {
+      readOnlyHint: false,
+      destructiveHint: false,
+      idempotentHint: false,
+      openWorldHint: false,
     }
   },
   async ({ entities }) => {
@@ -291,6 +297,12 @@ server.registerTool(
     },
     outputSchema: {
       relations: z.array(RelationSchema)
+    },
+    annotations: {
+      readOnlyHint: false,
+      destructiveHint: false,
+      idempotentHint: false,
+      openWorldHint: false,
     }
   },
   async ({ relations }) => {
@@ -319,6 +331,12 @@ server.registerTool(
         entityName: z.string(),
         addedObservations: z.array(z.string())
       }))
+    },
+    annotations: {
+      readOnlyHint: false,
+      destructiveHint: false,
+      idempotentHint: false,
+      openWorldHint: false,
     }
   },
   async ({ observations }) => {
@@ -342,6 +360,12 @@ server.registerTool(
     outputSchema: {
       success: z.boolean(),
       message: z.string()
+    },
+    annotations: {
+      readOnlyHint: false,
+      destructiveHint: true,
+      idempotentHint: true,
+      openWorldHint: false,
     }
   },
   async ({ entityNames }) => {
@@ -368,6 +392,12 @@ server.registerTool(
     outputSchema: {
       success: z.boolean(),
       message: z.string()
+    },
+    annotations: {
+      readOnlyHint: false,
+      destructiveHint: true,
+      idempotentHint: true,
+      openWorldHint: false,
     }
   },
   async ({ deletions }) => {
@@ -391,6 +421,12 @@ server.registerTool(
     outputSchema: {
       success: z.boolean(),
       message: z.string()
+    },
+    annotations: {
+      readOnlyHint: false,
+      destructiveHint: true,
+      idempotentHint: true,
+      openWorldHint: false,
     }
   },
   async ({ relations }) => {
@@ -412,6 +448,12 @@ server.registerTool(
     outputSchema: {
       entities: z.array(EntitySchema),
       relations: z.array(RelationSchema)
+    },
+    annotations: {
+      readOnlyHint: true,
+      destructiveHint: false,
+      idempotentHint: true,
+      openWorldHint: false,
     }
   },
   async () => {
@@ -435,6 +477,12 @@ server.registerTool(
     outputSchema: {
       entities: z.array(EntitySchema),
       relations: z.array(RelationSchema)
+    },
+    annotations: {
+      readOnlyHint: true,
+      destructiveHint: false,
+      idempotentHint: true,
+      openWorldHint: false,
     }
   },
   async ({ query }) => {
@@ -458,6 +506,12 @@ server.registerTool(
     outputSchema: {
       entities: z.array(EntitySchema),
       relations: z.array(RelationSchema)
+    },
+    annotations: {
+      readOnlyHint: true,
+      destructiveHint: false,
+      idempotentHint: true,
+      openWorldHint: false,
     }
   },
   async ({ names }) => {