diff --git a/docs-devsite/vertexai-preview.generationconfig.md b/docs-devsite/vertexai-preview.generationconfig.md
index 3b00214d88b..b14dfea053b 100644
--- a/docs-devsite/vertexai-preview.generationconfig.md
+++ b/docs-devsite/vertexai-preview.generationconfig.md
@@ -26,7 +26,7 @@ export interface GenerationConfig
 |  [frequencyPenalty](./vertexai-preview.generationconfig.md#generationconfigfrequencypenalty) | number |  |
 |  [maxOutputTokens](./vertexai-preview.generationconfig.md#generationconfigmaxoutputtokens) | number |  |
 |  [presencePenalty](./vertexai-preview.generationconfig.md#generationconfigpresencepenalty) | number |  |
-|  [responseMimeType](./vertexai-preview.generationconfig.md#generationconfigresponsemimetype) | string | Output response mimetype of the generated candidate text. Supported mimetype: <code>text/plain</code>: (default) Text output. <code>application/json</code>: JSON response in the candidates. The model needs to be prompted to output the appropriate response type, otherwise the behavior is undefined. This is a preview feature. |
+|  [responseMimeType](./vertexai-preview.generationconfig.md#generationconfigresponsemimetype) | string | Output response mimetype of the generated candidate text. Supported mimetypes are <code>text/plain</code> (default, text output) and <code>application/json</code> (JSON response in the candidates). The model needs to be prompted to output the appropriate response type, otherwise the behavior is undefined. This is a preview feature. |
 |  [stopSequences](./vertexai-preview.generationconfig.md#generationconfigstopsequences) | string\[\] |  |
 |  [temperature](./vertexai-preview.generationconfig.md#generationconfigtemperature) | number |  |
 |  [topK](./vertexai-preview.generationconfig.md#generationconfigtopk) | number |  |
@@ -66,7 +66,7 @@ presencePenalty?: number;
 
 ## GenerationConfig.responseMimeType
 
-Output response mimetype of the generated candidate text. Supported mimetype: `text/plain`<!-- -->: (default) Text output. `application/json`<!-- -->: JSON response in the candidates. The model needs to be prompted to output the appropriate response type, otherwise the behavior is undefined. This is a preview feature.
+Output response mimetype of the generated candidate text. Supported mimetypes are `text/plain` (default, text output) and `application/json` (JSON response in the candidates). The model needs to be prompted to output the appropriate response type, otherwise the behavior is undefined. This is a preview feature.
 
 <b>Signature:</b>
 
diff --git a/packages/vertexai/src/types/requests.ts b/packages/vertexai/src/types/requests.ts
index 5da8f05b6bb..f348a62aa6f 100644
--- a/packages/vertexai/src/types/requests.ts
+++ b/packages/vertexai/src/types/requests.ts
@@ -79,9 +79,8 @@ export interface GenerationConfig {
   frequencyPenalty?: number;
   /**
    * Output response mimetype of the generated candidate text.
-   * Supported mimetype:
-   *   `text/plain`: (default) Text output.
-   *   `application/json`: JSON response in the candidates.
+   * Supported mimetypes are `text/plain` (default, text output) and `application/json`
+   * (JSON response in the candidates).
    * The model needs to be prompted to output the appropriate response type,
    * otherwise the behavior is undefined.
    * This is a preview feature.