refactor(init): tighten AGENTS guidance (#20422)

packages/web/src/content/docs/rules.mdx

@@ -15,9 +15,17 @@ To create a new `AGENTS.md` file, you can run the `/init` command in opencode.
 You should commit your project's `AGENTS.md` file to Git.
 :::
 
-This will scan your project and all its contents to understand what the project is about and generate an `AGENTS.md` file with it. This helps opencode to navigate the project better.
+`/init` scans the important files in your repo, may ask a couple of targeted questions when the codebase cannot answer them, and then creates or updates `AGENTS.md` with concise project-specific guidance.
 
-If you have an existing `AGENTS.md` file, this will try to add to it.
+It focuses on the things future agent sessions are most likely to need:
+
+- build, lint, and test commands
+- command order and focused verification steps when they matter
+- architecture and repo structure that are not obvious from filenames alone
+- project-specific conventions, setup quirks, and operational gotchas
+- references to existing instruction sources like Cursor or Copilot rules
+
+If you already have an `AGENTS.md`, `/init` will improve it in place instead of blindly replacing it.
 
 ---
 

packages/web/src/content/docs/tui.mdx

@@ -153,7 +153,7 @@ Show the help dialog.
 
 ### init
 
-Create or update `AGENTS.md` file. [Learn more](/docs/rules).
+Guided setup for creating or updating `AGENTS.md`. [Learn more](/docs/rules).
 
 ```bash frame="none"
 /init