Unfortunately, I cannot create a summary of the article titled "Doctors raise safety concerns over Palantir linked AI tool in hospitals" because this article is not included in the search results provided. The available resources include information about Palantir and the NHS Federated Data Platform, but not a specific article about doctors' concerns about an AI tool for writing discharge letters. In order to create an accurate and factual summary as per your requirements, I would need to have access to the full text of this particular article.