diff --git a/AGENTS.md b/AGENTS.md
index d3adb95..a44598c 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -60,6 +60,23 @@ Some reference pages are generated from source repositories. Do not edit these f
 - **Protobuf schemas** (`docs/reference/schemas/{notification,policy}.md`): generated by `protoc-gen-doc` from proto definitions in the API server repo. Regenerate with `make generate-proto-docs APISERVER_DIR=<path>`.
 - **OpenAPI specs** (`docs/reference/api/openapi-*.yaml`): downloaded from API server CI artifacts via the `update-openapi-docs` workflow.
 
+## Language and style
+
+Follow the [Google developer documentation style guide](https://developers.google.com/style). Vale enforces the machine-checkable subset (Oxford commas, contractions, em-dashes, semicolons, slang, sentence-case headings, date formats, passive voice, banned words). Apply the rest by hand:
+
+- Short sentences, active voice, common words. Domain terms (CEL, SBOM, outbox) are fine where they carry weight.
+- No idioms, metaphors, or cultural references — readers translate these docs with machine tools.
+- American English spellings (color, organize, behavior, summarize, centralized, normalize).
+- Address the reader as "you", never "the user".
+- No filler or condescension: "simply", "just", "easy", "obvious", "merely", "basically", "please".
+- No positional references ("above", "below", "earlier"). Link to the section by name instead.
+- Descriptive link text. Never "click here", "here", or "this page".
+- "Select" for UI actions, not "click". Bold for UI labels. Backticks for code, commands, paths, env vars, and identifiers.
+- Abbreviations in `docs/includes/abbreviations.md` need no first-use expansion (MkDocs renders a hover tooltip). Spell out others on first use per page, and add the abbreviation to that file if it spans more than one page.
+- Numbers zero–nine spelled out, 10+ as numerals. Always numerals for versions, ports, durations, and units.
+
+Where Google style conflicts with `context/diataxis-contract.md`, Diataxis wins. Notably: Tutorials use "we" (tutor-learner partnership) and "will" to set expectations; Guides, Concepts, and Reference use "you" or no pronoun.
+
 ## Writing conventions
 
 - Do not modify files in `existing-docs/`.
@@ -67,6 +84,7 @@ Some reference pages are generated from source repositories. Do not edit these f
 - Use ATX-style headings (`# Heading`), not setext.
 - Inline HTML is allowed (admonitions, tabs).
 - No line length limit for Markdown prose.
+- End linted Markdown files in `docs/` and `context/` with a single trailing newline (markdownlint MD047).
 - YAML indentation: 2 spaces, no document-start markers.
 - Vale enforces Google developer style and write-good rules. Accepted/rejected terms are in `.vale/styles/config/vocabularies/DependencyTrack/`.
 - Page-specific images mirror the docs tree under `docs/assets/images/`: an image used by `docs/<section>/<page>.md` lives at `docs/assets/images/<section>/<page>/<name>.<ext>`. Shared assets (e.g. `logo.svg`) stay at the root of `docs/assets/images/`.