Read the catalog before the books.
You enter a library looking for a rain plan. A librarian does not dump every book onto your desk. First you scan the catalog. Then you look around one promising entry. Finally, you open the record you actually need.
Source book by 递归客 (diguike) · Full attribution
Recognition comes before detail
Progressive disclosure means revealing information in useful layers. A small index tells the agent what exists. A timeline shows nearby activity. A detailed observation supplies the full note when it is worth reading.
The book describes a search → timeline → get_observations workflow. Those are tool names, but the idea is familiar: find a candidate, understand its surroundings, then read the relevant detail. Every layer has a cost in tokens and time. There are tasks where fetching detail directly is sensible; the layers are a strategy, not a ritual.
Find the rain plan without opening everything
Reading all three details with the index and timeline would cost 232 tokens in this invented example. Each record is counted once in this experiment.
Fictional example. This experiment runs locally and does not call an AI or access your memory.
The timeline gives the note its place
A note saying ‘use the courtyard’ may look useful until the next note says ‘courtyard unavailable; reserve the indoor room.’ Neighbors reveal change, cause, and uncertainty that an isolated search hit can conceal.
Do not mistake a good match for the latest truth. Dates and supporting evidence help you decide which note applies now. If records disagree, the system needs to surface the disagreement rather than quietly choosing whichever sounded similar.
MCP is the conversation with the librarian
MCP, the Model Context Protocol, gives an agent a standard way to discover and call connected tools. A memory search tool can use that connection to return notes from an external store.
MCP does not give every app automatic access to everything. A client needs a supported connection and the right permissions. The protocol supplies the interface; storage, retrieval quality, and access rules are separate responsibilities. A shared door to the library still needs a key.
Behind this lesson
Related chapters in 递归客’s original book:
The source examines Claude-Mem v12.6.2. Links are pinned to the book revision used for this course; current implementation details may differ.