docs: update docstrings for better formatting (#3838)

# What does this PR do?
Updates docstrings for Conversations and Eval APIs to render better in
the docs nav sidebar.

Before: 
<img width="363" height="233" alt="Screenshot 2025-10-17 at 9 52 17 AM"
src="https://github.com/user-attachments/assets/3a77f9e3-3b03-43ae-8584-a21d1f44d54d"
/>

After:
<img width="410" height="206" alt="Screenshot 2025-10-17 at 9 52 11 AM"
src="https://github.com/user-attachments/assets/fa5d428d-2bde-4453-84fd-9aceebe712e8"
/>


## Test Plan
* Manual testing

docs/static/stainless-llama-stack-spec.yaml

@@ -195,7 +195,10 @@ paths:
       tags:
         - Conversations
       summary: Create a conversation.
-      description: Create a conversation.
+      description: >-
+        Create a conversation.
+
+        Create a conversation.
       parameters: []
       requestBody:
         content:
@@ -225,8 +228,11 @@ paths:
           $ref: '#/components/responses/DefaultError'
       tags:
         - Conversations
-      summary: Get a conversation with the given ID.
-      description: Get a conversation with the given ID.
+      summary: Retrieve a conversation.
+      description: >-
+        Retrieve a conversation.
+
+        Get a conversation with the given ID.
       parameters:
         - name: conversation_id
           in: path
@@ -255,9 +261,10 @@ paths:
           $ref: '#/components/responses/DefaultError'
       tags:
         - Conversations
-      summary: >-
-        Update a conversation's metadata with the given ID.
+      summary: Update a conversation.
       description: >-
+        Update a conversation.
+
         Update a conversation's metadata with the given ID.
       parameters:
         - name: conversation_id
@@ -293,8 +300,11 @@ paths:
           $ref: '#/components/responses/DefaultError'
       tags:
         - Conversations
-      summary: Delete a conversation with the given ID.
-      description: Delete a conversation with the given ID.
+      summary: Delete a conversation.
+      description: >-
+        Delete a conversation.
+
+        Delete a conversation with the given ID.
       parameters:
         - name: conversation_id
           in: path
@@ -324,8 +334,11 @@ paths:
           $ref: '#/components/responses/DefaultError'
       tags:
         - Conversations
-      summary: List items in the conversation.
-      description: List items in the conversation.
+      summary: List items.
+      description: >-
+        List items.
+
+        List items in the conversation.
       parameters:
         - name: conversation_id
           in: path
@@ -498,8 +511,11 @@ paths:
           $ref: '#/components/responses/DefaultError'
       tags:
         - Conversations
-      summary: Create items in the conversation.
-      description: Create items in the conversation.
+      summary: Create items.
+      description: >-
+        Create items.
+
+        Create items in the conversation.
       parameters:
         - name: conversation_id
           in: path
@@ -535,8 +551,11 @@ paths:
           $ref: '#/components/responses/DefaultError'
       tags:
         - Conversations
-      summary: Retrieve a conversation item.
-      description: Retrieve a conversation item.
+      summary: Retrieve an item.
+      description: >-
+        Retrieve an item.
+
+        Retrieve a conversation item.
       parameters:
         - name: conversation_id
           in: path
@@ -571,8 +590,11 @@ paths:
           $ref: '#/components/responses/DefaultError'
       tags:
         - Conversations
-      summary: Delete a conversation item.
-      description: Delete a conversation item.
+      summary: Delete an item.
+      description: >-
+        Delete an item.
+
+        Delete a conversation item.
       parameters:
         - name: conversation_id
           in: path
@@ -13533,17 +13555,17 @@ tags:
   - name: Benchmarks
     description: ''
   - name: Conversations
-    description: ''
-    x-displayName: >-
+    description: >-
       Protocol for conversation management operations.
+    x-displayName: Conversations
   - name: DatasetIO
     description: ''
   - name: Datasets
     description: ''
   - name: Eval
-    description: ''
-    x-displayName: >-
+    description: >-
       Llama Stack Evaluation API for running evaluations on model and agent candidates.
+    x-displayName: Evaluations
   - name: Files
     description: >-
       This API is used to upload documents that can be used with other Llama Stack