docs content: meta descriptions too thin to serve as snippets — median 46 chars, 228 of 403 under 70

[os-zhuang]

One-liner

Every page has a description (good), but the median is 46 characters and 228 of 403 are under 70 — far below the ~155 characters a result gets. Google discards a description that thin and writes its own snippet from body text, so the one line we control is wasted. At the other end, 42 pages run past 160 and get cut mid-sentence.

Measured

description length: n=403 min=20 median=46 max=381 <70 chars: 228 >160 chars: 42

Expected

• Rewrite to 120–155 characters: what the page lets you do, in the words a reader would search, ending on a reason to click.
• Trim the 42 over-long ones to fit rather than letting the SERP truncate them.
• Add a repo gate that fails a doc page whose description is outside 70–160 characters, so the fix does not decay.

⚠️ Same maintainer-voice caveat as the page-title card: ship the rule and the table in the PR body, leave it for maintainer review, do not self-merge.

Acceptance

• every content/docs/** description is 70–160 characters
• a check:* gate enforces the range and runs in Lint & Repo Gates
• descriptions read as sentences, not as truncated titles

Source

Found in an SEO review of the docs site (apps/docs) run on 2026-08-25, measured against the local dev server and against production. The canonical origin is https://objectstack.ai — maintainer ruling recorded in #10659:

这个仓的文档站规范 URL 是 https://objectstack.ai

[os-zhuang]

Held — hard serial on content/docs/**, behind #12236 and then #12237. Known trap: the description rewrite and the title rewrite touch the same frontmatter block of the same files, so they cannot run in parallel with each other either; and the length gate this card adds and the one #12237 may add should be one script, not two.