Claude Platform Uses BM25 for Tool Search but Leaves Memory Retrieval to Path Navigation

Anthropic's Claude Developer Platform handles context overflow differently for its tool catalog and memory store, according to documentation reviewed in September 2026. For tools, the platform offers built-in BM25 and regex search, returning up to five ranked matches so the model never loads the full catalog into context. The memory store, by contrast, can hold up to 10,000 entries but offers no search or relevance ranking — retrieval relies solely on path prefix and depth parameters, similar to filesystem commands like ls and find. Items in the memory store are returned in a stable, server-defined order rather than by relevance, meaning the model must determine relevance from a listing. Anthropic's documentation advises tool authors to write clear names and descriptions to improve search accuracy, but no equivalent naming guidance exists for memory paths, even though path segments function as the sole retrieval selectors.