docs: clarify session event coverage page

Author: NathanFlurry

README.md

@@ -17,34 +17,7 @@
 
 [Documentation](https://sandboxagent.dev/docs) — [Discord](https://rivet.dev/discord)
 
-## Universal Schema Support
-
-Which agent features are normalized into the universal event schema. All agents have full native capabilities; this shows what's exposed via the API.
-
-| Feature            | Claude | Codex | OpenCode     | Amp          |
-|--------------------|:------:|:-----:|:------------:|:------------:|
-| Stability          | Stable | Stable| Experimental | Experimental |
-| Text Messages      |   ✓    |   ✓   |      ✓       |      ✓       |
-| Tool Calls         |   ✓    |   ✓   |      ✓       |      ✓       |
-| Tool Results       |   ✓    |   ✓   |      ✓       |      ✓       |
-| Questions (HITL)   |   ✓    |       |      ✓       |              |
-| Permissions (HITL) |   ✓    |   ✓   |      ✓       |      -       |
-| Images             |   -    |   ✓   |      ✓       |      -       |
-| File Attachments   |   -    |   ✓   |      ✓       |      -       |
-| Session Lifecycle  |   -    |   ✓   |      ✓       |      -       |
-| Error Events       |   -    |   ✓   |      ✓       |      ✓       |
-| Reasoning/Thinking |   -    |   ✓   |              |              |
-| Command Execution  |   -    |   ✓   |              |              |
-| File Changes       |   -    |   ✓   |              |              |
-| MCP Tools          |   -    |   ✓   |              |              |
-| Streaming Deltas   |   ✓    |   ✓   |      ✓       |      -       |
-
-Agents: [Claude Code](https://docs.anthropic.com/en/docs/agents-and-tools/claude-code/overview) · [Codex](https://github.com/openai/codex) · [OpenCode](https://github.com/opencode-ai/opencode) · [Amp](https://ampcode.com)
-
-- ✓ = Supported in universal schema
-- \- = Schema support in progress
-
-Want support for another agent? [Open an issue](https://github.com/rivet-dev/sandbox-agent/issues/new) to request it.
+Want support for another agent or sandbox provider? [Open an issue](https://github.com/rivet-dev/sandbox-agent/issues/new) to request it.
 
 ## Architecture
 

docs/agent-compatibility.mdx

@@ -1,12 +1,14 @@
 ---
-title: "Universal Schema Support"
-description: "Which agent features are exposed through the universal API."
+title: "Session Event Coverage"
+description: "What appears in your session transcript for each agent."
 icon: "table"
 ---
 
-The universal API normalizes different coding agents into a consistent interface. All agents have full native capabilities; this page shows what's exposed via the sandbox-agent API.
+Each coding agent outputs events in its own native format. The sandbox-agent converts these into a [universal event schema](/docs/universal-schema), giving you a consistent session transcript regardless of which agent you use.
 
-## Feature Matrix
+This page shows which agent capabilities appear in the universal event stream. All agents retain their full native capabilities—this only reflects what's normalized into the universal schema.
+
+## Coverage Matrix
 
 | Feature            | Claude | Codex | OpenCode     | Amp          |
 |--------------------|:------:|:-----:|:------------:|:------------:|
@@ -28,8 +30,9 @@ The universal API normalizes different coding agents into a consistent interface
 
 Agents: [Claude Code](https://docs.anthropic.com/en/docs/agents-and-tools/claude-code/overview) · [Codex](https://github.com/openai/codex) · [OpenCode](https://github.com/opencode-ai/opencode) · [Amp](https://ampcode.com)
 
-- ✓ = Supported in universal schema
-- \- = Schema support in progress
+- ✓ = Appears in session events
+- \- = Agent supports natively, schema conversion coming soon
+- (blank) = Not supported by agent
 
 ## Feature Descriptions