diff --git a/docs/concepts/context-engine.md b/docs/concepts/context-engine.md
index 5c6a885727c..da067b5f733 100644
--- a/docs/concepts/context-engine.md
+++ b/docs/concepts/context-engine.md
@@ -7,12 +7,13 @@ read_when:
 title: "Context engine"
 ---
 
-A **context engine** controls how OpenClaw builds model context for each run.
-It decides which messages to include, how to summarize older history, and how
-to manage context across subagent boundaries.
+A **context engine** controls how OpenClaw builds model context for each run:
+which messages to include, how to summarize older history, and how to manage
+context across subagent boundaries.
 
-OpenClaw ships with a built-in `legacy` engine. Plugins can register
-alternative engines that replace the active context-engine lifecycle.
+OpenClaw ships with a built-in `legacy` engine and uses it by default — most
+users never need to change this. Install and select a plugin engine only when
+you want different assembly, compaction, or cross-session recall behavior.
 
 ## Quick start
 
diff --git a/docs/plugins/building-plugins.md b/docs/plugins/building-plugins.md
index cbe48e62019..3efd942b98e 100644
--- a/docs/plugins/building-plugins.md
+++ b/docs/plugins/building-plugins.md
@@ -38,7 +38,7 @@ falls back to npm automatically.
   </Card>
 </CardGroup>
 
-If a channel plugin is optional and may not be installed when onboarding/setup
+For a channel plugin that isn't guaranteed to be installed when onboarding/setup
 runs, use `createOptionalChannelSetupSurface(...)` from
 `openclaw/plugin-sdk/channel-setup`. It produces a setup adapter + wizard pair
 that advertises the install requirement and fails closed on real config writes
diff --git a/docs/providers/anthropic.md b/docs/providers/anthropic.md
index e0701956145..4af9af62341 100644
--- a/docs/providers/anthropic.md
+++ b/docs/providers/anthropic.md
@@ -278,11 +278,11 @@ OpenClaw supports Anthropic's prompt caching feature for API-key auth.
 
 <AccordionGroup>
   <Accordion title="401 errors / token suddenly invalid">
-    Anthropic token auth can expire or be revoked. For new setups, migrate to an Anthropic API key.
+    Anthropic token auth expires and can be revoked. For new setups, use an Anthropic API key instead.
   </Accordion>
 
   <Accordion title='No API key found for provider "anthropic"'>
-    Auth is **per agent**. New agents don't inherit the main agent's keys. Re-run onboarding for that agent, or configure an API key on the gateway host, then verify with `openclaw models status`.
+    Anthropic auth is **per agent** — new agents do not inherit the main agent's keys. Re-run onboarding for that agent (or configure an API key on the gateway host), then verify with `openclaw models status`.
   </Accordion>
 
   <Accordion title='No credentials found for profile "anthropic:default"'>
diff --git a/docs/providers/xai.md b/docs/providers/xai.md
index a80e293128d..31551a38137 100644
--- a/docs/providers/xai.md
+++ b/docs/providers/xai.md
@@ -64,7 +64,9 @@ current image-capable Grok refs in the bundled catalog.
 ## OpenClaw feature coverage
 
 The bundled plugin maps xAI's current public API surface onto OpenClaw's shared
-provider and tool contracts where the behavior fits cleanly.
+provider and tool contracts. Capabilities that don't fit the shared contract
+(for example streaming TTS and realtime voice) are not exposed — see the table
+below.
 
 | xAI capability             | OpenClaw surface                          | Status                                                              |
 | -------------------------- | ----------------------------------------- | ------------------------------------------------------------------- |