Claude Corner

Turn on citations.enabled on every document block so Claude returns structured locations instead of freeform "according to the docs" prose. Prefer plain text or PDF for sentence chunking, or custom content blocks when you need RAG-chunk granularity. Do not combine citations with output_config.format JSON schema. The API returns 400 because citation spans cannot satisfy a … Read more

Tip-only: lock a tool-free Messages reply to a JSON Schema with output_config.format so parsers stop stripping markdown fences.

Tip-only: pin Messages API tool_choice (auto, any, tool, none) and disable_parallel_tool_use so agent loops get deterministic tool turns.

Tip-only: place Anthropic prompt-cache breakpoints on the static tools and system prefix; clear the 512-token floor on Opus 5-class models.