Context engineering

Secondary source

A secondary source is second-hand information: blog posts, summaries, or the model's own memory. It is useful for orientation but must be checked against the primary source before you rely on it.

James Phoenix
Understanding Data Updated July 2, 2026

A secondary source is second-hand information: a blog post, a forum answer, a tutorial, a summary, or the model's own recollection from training. It is someone's account of the thing rather than the thing itself. Handy for getting oriented, not safe to build on unchecked.

The trap

Secondary sources feel authoritative and are easy to reach, so it is tempting to stop there. But they go stale, they simplify, and they are sometimes just wrong. The model's own memory is the sneakiest one of all, because it presents a half-remembered API with the same confidence as a fact. That is a short hop from a hallucination: plausible, fluent, and wrong.

Where secondary sources earn their keep:

  • Getting the lay of the land on an unfamiliar topic.
  • Finding the name of the thing you should then go and verify.
  • Sanity-checking your own understanding before you commit.

Always resolve to the original

Use a secondary source to point yourself at the primary source, then confirm. Reading the real docs turns a vague recollection into contextual knowledge the agent can actually trust. Orientation is fine; verification is mandatory.

Watch out
Treat any API, flag, or version detail that came from a secondary source as unverified. The cost of checking is one file read. The cost of not checking is a bug that looks correct until it runs.

Related terms

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