The four lenses — read before this ships

Load when: a change of consequence is about to land — a release, a merge into the guide, a new capability, a rewritten rule. Also on request: "run the lenses over this."

Four readings, one question each, in this order, by someone who is not the author. They are the compensating control for every prose-only gate — the reason it is honest to write enforced_by: prose-only at all is that these run.

Why four separate readings instead of one careful one. A reader holding four questions holds none of them. Each lens is cheap because it ignores everything except its own question, and the order matters: deleting first means the later lenses read less.

Why not the author. Not distrust — the author's context is invisible to the author. They cannot see what they assumed, because assuming it is what made the text feel complete.

1 · Deletion — what can go?

Fights: additive drift.

• What breaks if this is simply removed?
• Does it restate a rule that already lives somewhere? (If so, one of the two is the home and the other points.)
• Is a new entity doing work an existing one could do with one more value?
• Is this a pattern already named in ./patterns, being paraphrased instead of cited?

The bar is not "is this good" but "would we notice it gone". A change that survives deletion is the smallest version of itself, and that is the only version worth reviewing further.

2 · Adversarial — how does this fail?

Fights: authors test what they intended.

• The unhappy path. Misuse by someone in a hurry.
• Does a failure fail loudly or quietly? A gate that fails open is worse than no gate, because it is believed.
• What does a half-finished write leave behind?
• What is the cheapest way to comply with the letter and violate the rule?
• Who pays for it — in tokens, in attention, in a wait nobody sees?

3 · Contradiction — does this fight anything?

Fights: local correctness.

Against the corpus, not against taste. Name both sides, with locations.

• Does it promise something nothing delivers — a referenced file that does not exist, a check described but not implemented, a capability no door reaches?
• Does it use a glossary term in a second meaning?
• A reversal is legitimate; an unstated one is not. If this overturns an earlier decision, say so and say why, and the earlier decision gets its revisit note.

4 · Cold-read — understandable by someone who was not here?

Fights: the author's context is invisible to the author.

• Does it explain why, not only what?
• Does it depend on context that exists only in a conversation?
• Would a newcomer act correctly from this text alone — or correctly by accident?
• Is the example still an example of the rule, or did the rule move?

Running them

Each lens is stated, including when it found nothing. "Deletion: nothing found" is a result; silence is indistinguishable from a skipped lens.

A finding names its place and its fix: path, line, the defect in one sentence, and what would resolve it. A finding without a location is an opinion.

Findings are not votes. The lenses report; the owner of the change decides, and a rejected finding is answered, not ignored — one line saying why.

They run on this skill and on the user's project alike. The corpus is not more fragile than the work; the same four questions catch the same four failures in a spec, a role's instructions or a pipeline change.

Temporary readers. When they run as agents, they are created for the release and archived after — they read, they do not own. Archiving them is part of finishing the release (./patterns → promote what outgrew itself does not apply here: a lens never grows into a role).

What the lenses do not cover

They read text. They do not run the code, walk the links, or measure a number — those are ./checking and the eval suite. Four green lenses over a claim that was never true is exactly the failure mode the corpus names: a statement that parsed perfectly, linked correctly, and was false. The six reading rules in ./contributing are the companion habit for that, and the eval pass-rate is the measurement.