docs: Updates IAM topics

website/content/docs/common-workflows/manage-roles.mdx

@@ -1,7 +1,8 @@
 ---
 layout: docs
 page_title: Manage roles and permissions
-description: How to manage roles, permissions, and grants.
+description: >-
+  Use roles to manage permissions assigned to users and groups. Create roles and assign principals and grants to them. Add grant scopes and configure inheritance.
 ---
 
 # Manage roles and permissions

website/content/docs/configuration/identity-access-management/assignable-permissions.mdx

@@ -1,8 +1,8 @@
 ---
 layout: docs
 page_title: Assignable permissions
-description: |-
-  Assignable permissions
+description: >-
+  Learn about using actions and output fields to grant users permissions to any resources that are identified by ID or Type.
 ---
 
 # Assignable permissions

website/content/docs/configuration/identity-access-management/index.mdx

@@ -1,8 +1,8 @@
 ---
 layout: docs
 page_title: Permissions index
-description: |-
-  Boundary's permissions model
+description: >-
+  Learn about Boundary's RBAC, allow-only permissions model. Understand how permissions are configured using grant strings and roles.
 ---
 
 # Permissions in Boundary

website/content/docs/configuration/identity-access-management/permission-grant-formats.mdx

@@ -1,8 +1,8 @@
 ---
 layout: docs
 page_title: Permission grant formats
-description: |-
-  Permission grant formats
+description: >-
+  Learn how to construct grant strings that map resources and permissions. Understand ID, Type, Pinned, and Wildcard grant formats.View possible grant templates.
 ---
 
 # Permission grant formats

website/content/docs/configuration/identity-access-management/resource-table.mdx

@@ -1,8 +1,8 @@
 ---
 layout: docs
 page_title: Resource table
-description: |-
-  Resource table
+description: >-
+  View a list of resources and their available permissions parameters and actions to help you configure and manage permissions.
 ---
 
 # Resource tables