Four numbers, checked monthly. Their direction over time tells you whether the system is working, which is not obvious from using it day to day.
python3 scripts/vault_stats.py ~/brainPages with no inbound links, as a share of all pages.
The single most diagnostic number in the vault. A rising orphan rate means ingestion is writing pages without connecting them, which is the exact failure mode that turns a wiki back into a folder.
Under five percent is healthy. Over fifteen and something is broken in the ingest instructions, not in your habits.
Links per page.
Below two, the graph is barely connected and retrieval cannot do better than search. Between three and eight is the working range for a personal vault. Much above ten, check whether links are being added decoratively, which inflates the number while making the graph less useful.
Watch it alongside page count. Degree that stays flat while the vault doubles is fine; degree that falls means new pages are attaching to less than the existing ones did.
How many disconnected islands.
Ideally one large component holding most pages, plus a few genuinely separate topics. If the main component holds less than about eighty percent of pages, the vault is fragmented and answers will be systematically incomplete without anything appearing wrong.
Concept pages whose updated date is older than ninety days, as a share of
concept pages.
Some staleness is correct: a well-written page on a settled idea does not need touching. But a vault where most concept pages have not been touched in months while sources keep arriving means new material is landing in new pages instead of updating existing ones. That is how you end up with four pages about one thing.
TABLE updated FROM "wiki/concepts"
WHERE updated < date(today) - dur(90 days)
SORT updated ASC
Page count and word count. Both go up regardless of whether the vault is getting better, which makes them satisfying and useless. A vault that doubled its pages while doubling its orphan rate got worse.
Append the four numbers to a note monthly. Trend is the information; a single reading tells you almost nothing, and you will not remember what last quarter's orphan rate was.
Agents, for running all of this without you.