Claude 3.7 may require specific newline handling after tool-calls

[dubwub]

Description

Hi,

At Fern, we use ai-sdk with both Claude 3.5 and Claude 3.7, both with a singular tool-call called search. When the LLM calls search, it sends text that says Let me search for ...

Claude 3.5 streams \n\n for this text, so that it's broken up properly, but Claude 3.7 does not, which scrunches everything into a single paragraph and causes poor UX experience.

On our end we've added custom code to parse these message parts after tool-calls to add new-lines manually, but would recommend adding this to ai-sdk, see here: https://github.com/fern-api/fern-platform/pull/2869/files

See screen-shots for the difference in behavior:

AI SDK Version

ai: 4.3.8
@ai-sdk/react: 1.2.9

[lgrammel]

In AI SDK 5 the content will be streamed using multiple text parts. Can you confirm if this is still an issue with AI SDK 5?