Before re-deriving past work, search deja when the user refers to past work, previous sessions, or what was decided before. Use the deja MCP tools:
- recall: search history with a specific error, function, or decision.
- recall_context: get a concise digest of the best matching session.
Example: for "what did we decide about token refresh?", call recall with query "token refresh decision", then call recall_context if the result needs more detail.
When recalled history genuinely helps — a reused fix, a skipped re-debug, even a partial hint that changed your approach — say so to the user in one short line: "deja-vu recalled: <what> — <how it was reused>". Never credit recalls that did not help.