package client

import "fmt"

// ToolError is a failed MCP tool call or a parse of its result.
type ToolError struct {
	Name    string // MCP tool name
	Message string
	Err     error // transport/SDK/parse cause; may be nil
}

func (e *ToolError) Error() string {
	return "mcp " + e.Name + ": " + e.Message
}

func (e *ToolError) Unwrap() error {
	return e.Err
}

// ToolErrorf builds a ToolError. format may use %w so Unwrap works.
func ToolErrorf(name, format string, args ...any) *ToolError {
	err := fmt.Errorf(format, args...)
	return &ToolError{
		Name:    name,
		Message: err.Error(),
		Err:     err,
	}
}