Fix webpage content pagination logic error

Improve truncated content handling. Fix empty content return logic •

Author: danielaskdd

fetch/src/mcp_server_fetch/server.py

@@ -233,9 +233,21 @@ async def call_tool(name, arguments: dict) -> list[TextContent]:
         content, prefix = await fetch_url(
             url, user_agent_autonomous, force_raw=args.raw
         )
-        if len(content) > args.max_length:
-            content = content[args.start_index : args.start_index + args.max_length]
-            content += f"\n\n<error>Content truncated. Call the fetch tool with a start_index of {args.start_index + args.max_length} to get more content.</error>"
+        original_length = len(content)
+        if args.start_index >= original_length:
+            content = "<error>No more content available.</error>"
+        else:
+            truncated_content = content[args.start_index : args.start_index + args.max_length]
+            if not truncated_content:
+                content = "<error>No more content available.</error>"
+            else:
+                content = truncated_content
+                actual_content_length = len(truncated_content)
+                remaining_content = original_length - (args.start_index + actual_content_length)
+                # Only add the prompt to continue fetching if there is still remaining content
+                if actual_content_length == args.max_length and remaining_content > 0:
+                    next_start = args.start_index + actual_content_length
+                    content += f"\n\n<error>Content truncated. Call the fetch tool with a start_index of {next_start} to get more content.</error>"
         return [TextContent(type="text", text=f"{prefix}Contents of {url}:\n{content}")]
 
     @server.get_prompt()