feat: validate contact and group search args

internal/tools/isphere_contacts_test.go

@@ -74,3 +74,50 @@ func TestISphereSearchContactsToolReturnsJIDContacts(t *testing.T) {
 		t.Fatalf("source queries = %+v, want one unbounded receive query", fake.queries)
 	}
 }
+
+func TestISphereSearchContactsToolValidatesContractArgs(t *testing.T) {
+	fake := &fakeReceiveMessagesSource{
+		result: isphere.ReceiveMessagesResult{Messages: []isphere.Message{{
+			ID:         "msg-1",
+			SenderID:   "alice@imopenfire1-lanzhou",
+			ReceiverID: "bob@imopenfire1-lanzhou",
+		}}},
+	}
+	session, cleanup := connectToolsTestSession(t, func(server *mcp.Server) {
+		RegisterISphereContactTools(server, fake)
+	})
+	defer cleanup()
+
+	callResult, err := session.CallTool(context.Background(), &mcp.CallToolParams{
+		Name: ToolNameSearchContacts,
+		Arguments: map[string]any{
+			"query":             "alice",
+			"source_preference": "local_readonly",
+			"include_inactive":  true,
+			"cursor":            "",
+			"limit":             10,
+		},
+	})
+	if err != nil {
+		t.Fatalf("call with safe contract args: %v", err)
+	}
+	if callResult.IsError {
+		t.Fatalf("call result is error: %+v", callResult)
+	}
+
+	bridgeResult, err := session.CallTool(context.Background(), &mcp.CallToolParams{
+		Name:      ToolNameSearchContacts,
+		Arguments: map[string]any{"query": "alice", "source_preference": "bridge"},
+	})
+	if err == nil && !bridgeResult.IsError {
+		t.Fatalf("bridge source_preference was accepted before connector exists")
+	}
+
+	cursorResult, err := session.CallTool(context.Background(), &mcp.CallToolParams{
+		Name:      ToolNameSearchContacts,
+		Arguments: map[string]any{"query": "alice", "cursor": "next-page"},
+	})
+	if err == nil && !cursorResult.IsError {
+		t.Fatalf("non-empty cursor was accepted before pagination exists")
+	}
+}