The improve Demand Gen ad strength recommendation.

[Proto definition ![GitHub](https://developers.google.com/site-assets/logo-github.svg)](https://github.com/googleapis/googleapis/blob/master/google/ads/googleads/v26/resources/recommendation.proto)

| Fields ||
|---|---|
| ## `ad` | `string` Output only. The resource name of the ad that can be improved. |
| ## `ad_strength` | `https://developers.google.com/google-ads/api/reference/rpc/v26/AdStrengthEnum.AdStrength` Output only. The current ad strength. |
| ## `demand_gen_asset_action_items[]` | `string` Output only. A list of recommendations to improve the ad strength. |