Simon Willison’s Weblog

Long context prompting tips (via) Interesting tips here from Anthropic's documentation about how to best prompt Claude to work with longer documents.

Put longform data at the top: Place your long documents and inputs (~20K+ tokens) near the top of your prompt, above your query, instructions, and examples. This can significantly improve Claude’s performance across all models. Queries at the end can improve response quality by up to 30% in tests, especially with complex, multi-document inputs.

It recommends using not-quite-valid-XML to add those documents to those prompts, and using a prompt that asks Claude to extract direct quotes before replying to help it focus its attention on the most relevant information:

Find quotes from the patient records and appointment history that are relevant to diagnosing the patient's reported symptoms. Place these in <quotes> tags. Then, based on these quotes, list all information that would help the doctor diagnose the patient's symptoms. Place your diagnostic information in <info> tags.