diff --git a/src/pages/index.astro b/src/pages/index.astro
index 7576eb5..b8070de 100644
--- a/src/pages/index.astro
+++ b/src/pages/index.astro
@@ -74,6 +74,12 @@ const description =
         backend, so that content leaves the machine. Secret-shaped strings are replaced first, and
         screening can be turned off per server for content that has to stay put.
       </li>
+      <li>
+        <b>Not a reader of tool descriptions.</b> The tool list is compared against the one a server
+        first advertised, so a description that changes is caught. Nothing asks whether a
+        description was hostile to begin with, so a server that arrives already carrying an
+        instruction is caught only when it changes.
+      </li>
     </ul>
   </section>
 
@@ -145,6 +151,32 @@ agent-chaperone hook post    # after it returns, before the model reads it</code
     </p>
   </section>
 
+  <section id="toollist">
+    <h2>
+      When a server changes shape{' '}
+      <a class="anchor" href="#toollist" aria-label="Link to this section">
+        #
+      </a>
+    </h2>
+    <p>
+      A server describes its own tools, and the agent reads those descriptions as instructions about
+      what the tools are for. You decide to trust a server once, against the tools it advertised
+      that day, and nothing makes that decision again.
+    </p>
+    <p>
+      So the first list a server sends is recorded: a digest of each tool's description and input
+      schema, not the text. Every later list is compared against it, and a rewritten description, a
+      tool that appeared and a tool that vanished are each reported. The comparison is local. It
+      sends nothing anywhere and it needs no key.
+    </p>
+    <p>
+      It never withholds the list. A client that cannot read the tool list cannot call anything, so
+      a finding here is addressed to you rather than to the agent. Once you have looked at a change
+      and want it to become the new expectation, <code>agent-chaperone trust &lt;server&gt;</code>{' '}
+      accepts it, by forgetting what was recorded so that the next list is the one to expect.
+    </p>
+  </section>
+
   <section id="measured">
     <h2>
       What it caught, and what it missed