fix(docs): say the Vanta mimeType is ignored for File-input uploads

Every return path of downloadServableFileFromStorage yields a non-empty
contentType (a literal, getMimeTypeFromExtension's GENERIC_MIME_TYPE
fallback, or resolveServableDocBytes' constants/getContentType), so
resolved.contentType always wins at route.ts:79-81 and params.mimeType is
unreachable on that branch. It is not a fallback; it is ignored.

Author: waleedlatif1

apps/docs/content/docs/en/integrations/vanta.mdx

@@ -331,7 +331,7 @@ Upload an evidence file to a Vanta document. Requires credentials with the vanta
 | `documentId` | string | Yes | Unique ID of the document to attach the file to |
 | `file` | file | No | The evidence file to upload |
 | `fileName` | string | No | Optional file name override |
-| `mimeType` | string | No | MIME type of the file \(e.g., application/pdf\). Applied when uploading base64 content; for a file from the File input it is only a fallback, since the content type is normally resolved from storage. |
+| `mimeType` | string | No | MIME type of the file \(e.g., application/pdf\). Used only for base64 uploads; ignored for a file from the File input, whose content type is always resolved from storage. |
 | `description` | string | No | Description of the uploaded evidence \(e.g., "Q3 access review evidence"\) |
 | `effectiveAtDate` | string | No | ISO 8601 date indicating when the document is effective from |
 

apps/sim/tools/generated/tool-metadata.ts

@@ -64,7 +64,7 @@ export const vantaUploadDocumentFileTool: ToolConfig<
       required: false,
       visibility: 'user-or-llm',
       description:
-        'MIME type of the file (e.g., application/pdf). Applied when uploading base64 content; for a file from the File input it is only a fallback, since the content type is normally resolved from storage.',
+        'MIME type of the file (e.g., application/pdf). Used only for base64 uploads; ignored for a file from the File input, whose content type is always resolved from storage.',
     },
     description: {
       type: 'string',