feat(server): add Tool call error categories

cmd/invoke.go

@@ -1,36 +0,0 @@
-// Copyright 2026 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package cmd
-
-import (
-	"fmt"
-
-	"github.com/spf13/cobra"
-)
-
-func newInvokeCmd(root *Command) *cobra.Command {
-	return &cobra.Command{
-		Use:   "invoke",
-		Short: "Invoke a tool",
-		Run: func(cmd *cobra.Command, args []string) {
-			invoke(root)
-		},
-	}
-}
-
-
-func invoke(cmd *Command) {
-	fmt.Println("Hello, World! Here is one of my flags" + cmd.cfg.Address)
-}

cmd/root.go

@@ -396,8 +396,6 @@ func NewCommand(opts ...Option) *Command {
 	// wrap RunE command so that we have access to original Command object
 	cmd.RunE = func(*cobra.Command, []string) error { return run(cmd) }
 
-	baseCmd.AddCommand(newInvokeCmd(cmd))
-
 	return cmd
 }
 

internal/util/errors.go

@@ -0,0 +1,42 @@
+// Copyright 2025 Google LLC
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+package util
+
+import "fmt"
+
+type ErrorCategory string
+
+const (
+	CategoryAgent  ErrorCategory = "AGENT_ERROR"
+	CategoryServer ErrorCategory = "SERVER_ERROR"
+)
+
+// ToolboxError is the interface all custom errors must satisfy
+type ToolboxError interface {
+	error
+}
+
+// Agent Errors
+type AgentError struct{ Msg string }
+
+func (e *AgentError) Error() string           { return e.Msg }
+func (e *AgentError) Category() ErrorCategory { return CategoryAgent }
+
+// Server Errors
+type ServerError struct {
+	Msg   string
+	Cause error
+}
+
+func (e *ServerError) Error() string           { return fmt.Sprintf("%s: %v", e.Msg, e.Cause) }
+func (e *ServerError) Category() ErrorCategory { return CategoryServer }