This issue checks whether a page asking "What is X?" actually opens by defining X.

This issue checks whether a page asking "What is X?" actually opens by defining X.

A "what is" page is the clearest possible statement of intent: the reader wants a definition. The opening paragraph should be that definition, phrased so it survives being quoted with no surrounding context — "X is a …".

A passing implementation opens with a definitional sentence. A failing one opens with scene-setting, market context, or a story, and defines the term somewhere further down (or not at all).

Example: "Observability is the ability to understand a system's internal state from its outputs." passes. "Modern systems have never been more complex…" fails, however good the article is.

Definition queries are the most quotable queries there are. "What is X" has one right shape of answer, and an engine will quote whichever page provides it cleanly. A page that buries the definition loses to one that leads with it.

A definition must be context-free to be liftable. "It is the ability to…" cannot be quoted — the pronoun has no referent once extracted. "Observability is the ability to…" can.

Readers bounce fastest on definitional pages. Someone who asked what a term means and gets three paragraphs of preamble leaves. The bounce and the failed extraction have the same cause.

It is a first-paragraph edit. The definition is nearly always already on the page; this is about moving it to the front and phrasing it as a statement.

1. Open with "X is …" or "X refers to …". Use the exact term from your heading as the grammatical subject. Not "it", not "this".

2. Make the first sentence complete on its own. Read it aloud with nothing before it. If it still makes sense, an engine can quote it.

3. Keep it to one or two sentences. Definition first, then nuance, then the essay.

4. Move the hook down. The market-context opener is good writing for a newsletter and wrong for a definitional page. It can be the second paragraph.

5. Match the term exactly. If the heading says "answer engine optimisation", define "answer engine optimisation" — not "AEO", and not "this practice".

Optional: DefinedTerm structured data makes the definition explicit rather than inferred, which helps for glossary pages.

Note on scope: this check only runs when the page's own title or <h1> begins "What is" or "What are". It never fires on other pages.

Failing

<title>What is observability?</title>
<h1>What is observability?</h1>
<p>Companies everywhere are struggling with the growing complexity of their
production systems, and the tooling has not kept pace with the shift to
distributed architectures.</p>
<p>Observability is the ability to understand a system from its outputs…</p>

The definition is on the page — one paragraph too late to be the answer.

Passing

<title>What is observability?</title>
<h1>What is observability?</h1>
<p>Observability is the ability to understand a system's internal state from
the data it emits — logs, metrics and traces. It differs from monitoring in
that it answers questions you did not plan for in advance.</p>
<p>Companies everywhere are struggling with…</p>

Not evaluated

<title>Release notes</title>
<h1>Release notes</h1>

No definitional intent, so the check does not run.

PixyScan detects this from the HTML your server returns, without executing JavaScript.

1. Intent gate. The page's <title> and <h1> are read. The check proceeds only if either begins with What is or What are.

2. Substance gate. The page must have at least 150 words of body text.

3. Opening paragraph resolution. PixyScan takes the first <p> following the <h1> in document order, stopping at the next heading.

4. Definition test. The first ~240 characters of that paragraph are checked for definitional phrasing: is, are, refers to, means, or describes.

5. Reporting. If a "what is" page's opening paragraph shows none of that phrasing, the issue is raised once, including a preview of the opening so you can see what PixyScan read.

Deliberate limitation — when PixyScan stays silent: if no opening paragraph can be resolved as a sibling of the <h1> (for example the text is wrapped in intervening <div> layers), the check reports nothing rather than guessing. Ambiguous structure is not evidence of a missing definition.