Update description.

### 13.4.1 Description

With this operation a client can obtain the full content of a specific

_`@context`_ (only for _`@contexts`_ of kind ["Hosted"]{.HTML-Code} or

["ImplicitlyCreated"]{.HTML-Code}), which is currently stored in the broker's

internal storage, or its metadata (for all kinds of stored _`@contexts`_).

With this operation a client can obtain one of the following:

- The full content of a specific _`@context`_ (only for _`@contexts`_ of kind

  ["Hosted"]{.HTML-Code} or ["ImplicitlyCreated"]{.HTML-Code}), which is

  currently stored in the broker's internal storage

- An _`@context`_ array holding a specified _`@context`_ URL and the core

  _`@context`_ URL.

- metadata for all kinds of stored _`@context`_.

### 13.4.2 Use case diagram