fix: improve file-generator tool with presigned URLs and system prompts

- Add explicit logging to track presigned URL generation
- Remove fallback to sourceUrl to ensure presigned URLs are always used
- Add file generation capability to system prompts for all models
- Update tool description to prevent LLMs from including raw URLs in responses
- Add guide field to tool result for better user messaging

This ensures all file downloads work correctly with private S3 buckets
and improves model awareness of file generation capabilities.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: mrjasonroy

src/lib/ai/prompts.ts

@@ -96,6 +96,7 @@ You can assist with:
 - Analysis and problem-solving across various domains
 - Using available tools and resources to complete tasks
 - Adapting communication to user preferences and context
+- Generating downloadable files (CSV, JSON, PDF, code files, etc.) when users request data exports or file creation
 </general_capabilities>`;
 
   // Communication preferences
@@ -123,8 +124,9 @@ ${userPreferences.responseStyleExample}
     prompt += `
 
 - When using tools, briefly mention which tool you'll use with natural phrases
-- Examples: "I'll search for that information", "Let me check the weather", "I'll run some calculations"
+- Examples: "I'll search for that information", "Let me check the weather", "I'll run some calculations", "I'll generate that file for you"
 - Use \`mermaid\` code blocks for diagrams and charts when helpful
+- When users request data exports, file downloads, or structured data files, use the file-generator tool to create downloadable files
 </communication_preferences>`;
   }
 
@@ -177,6 +179,7 @@ ${userInfo.join("\n")}
 You excel at conversational voice interactions by:
 - Providing clear, natural spoken responses
 - Using available tools to gather information and complete tasks
+- Generating downloadable files when users request data exports or file creation
 - Adapting communication to user preferences and context
 </voice_capabilities>`;
 

src/lib/ai/tools/file-generator/index.ts

@@ -12,6 +12,7 @@ export type FileGeneratorToolResult = {
     size: number;
   }[];
   description?: string;
+  guide?: string;
 };
 
 export const fileGeneratorTool = createTool({
@@ -22,7 +23,9 @@ export const fileGeneratorTool = createTool({
 - Code files: Python, JavaScript, HTML, CSS, etc.
 - Structured data exports
 
-The tool will generate the file, upload it to storage, and provide a download link. Do not use this for images (use image-manager instead) or for simple text responses that don't need to be downloaded.`,
+The tool will generate the file, upload it to storage, and provide a download link. Do not use this for images (use image-manager instead) or for simple text responses that don't need to be downloaded.
+
+IMPORTANT: After invoking this tool, do NOT include file URLs in your text response. The download links are automatically displayed in the UI above your message. Simply acknowledge that the file(s) have been generated.`,
   inputSchema: z.object({
     files: z
       .array(
@@ -89,23 +92,48 @@ The tool will generate the file, upload it to storage, and provide a download li
             contentType: mimeType,
           });
 
+          logger.info("File uploaded:", {
+            key: uploaded.key,
+            sourceUrl: uploaded.sourceUrl,
+            hasGetDownloadUrl: !!serverFileStorage.getDownloadUrl,
+          });
+
           // Get presigned URL for private buckets if available
-          const downloadUrl = serverFileStorage.getDownloadUrl
-            ? await serverFileStorage.getDownloadUrl(uploaded.key)
-            : uploaded.sourceUrl;
+          let downloadUrl: string;
+          if (serverFileStorage.getDownloadUrl) {
+            downloadUrl = await serverFileStorage.getDownloadUrl(uploaded.key);
+            logger.info("Presigned URL generated:", {
+              downloadUrl,
+              isPresigned: downloadUrl.includes("X-Amz"),
+            });
+          } else {
+            downloadUrl = uploaded.sourceUrl;
+            logger.info("Using source URL (no getDownloadUrl):", {
+              downloadUrl,
+            });
+          }
 
           return {
-            url: downloadUrl || uploaded.sourceUrl,
+            url: downloadUrl,
             filename: uploaded.metadata.filename || file.filename,
             mimeType: uploaded.metadata.contentType || mimeType,
             size: uploaded.metadata.size || buffer.length,
           };
         }),
       );
 
+      const fileCount = uploadedFiles.length;
+      const guide =
+        fileCount > 0
+          ? fileCount === 1
+            ? "Your file has been generated successfully and is ready for download above. You can click the download button to save it to your device."
+            : `Your ${fileCount} files have been generated successfully and are ready for download above. You can click the download buttons to save them to your device.`
+          : undefined;
+
       return {
         files: uploadedFiles,
         description,
+        guide,
       };
     } catch (e) {
       logger.error(e);