You are tasked to plan how modifying a JSON object of a _site schema_, based on a given TypeScript type definition and an update message, and its localized labels. Follow these steps carefully:

# 1. Review the TypeScript type definition of the JSON structure

<site_schema_ts_defs>
{{siteSchemaTsDefs}}
</site_schema_ts_defs>

# 2. About fields

Fields can be either predefined fields or custom fields. Take a look at the predefined fields provided by the CMS:

<predefined_fields_json>
{{predefinedFields}}
</predefined_fields_json>

# 3. The current site schema

Examine the current JSON data, which conforms to the `JtSiteSchema` type:

<site_schema_json>
{{siteSchemaJson}}
</site_schema_json>

Also, the attached localized labels:

<localized_labels_json>
{{l10nJson}}
</localized_labels_json>

# 4. Read the user message that describes the required changes

<user_message>
{{updateMessage}}
</user_message>

# 5. When there is nothing to change

Evaluate wether the current schema already implements the update message. If there's nothing to do, provide an empty <task_details_md> tags and you're done.

# 6. When there are changes to do

Otherwise, if there is something to change, then rewrite the user's request as a detailed sequence of operations to be carried out one after the other.

Guidelines for reformulating into a detailed sequence of operations:

- All operations must be written in English.
- Write the list of operations as a bulleted list in Markdown format. Start each operation with the `*` character. And surround identifiers with backquotes.
- Operations will be executed sequentially, so they must be written in the order of execution.
- If the user's request is simple and doesn't need to be separated into several operations, write a list with a single operation.
- Describe each operation concisely in a few words.
- Make sure that the tree structure of node types is not broken. The `site` node is separate. Then, the root of the tree structure is the `home` routing document. Every other routing document type, regular document type, part type, must be the child of another node type.
- Prefer predefined fields where you can. In particular, you can use the `"gallery"` field when the user description is a synonym (carousel, slider, slideshow, image gallery).
- Never use the same field twice in a list of fields.

Be the the less creative as possible. Follow the instructions. In particular:

- You are allowed to be proactive, but only when the user asks you to do something.
- Do not invent technical "fields" like sibling previous/next links. These are managed by the theme.
- Do not manage media policies unless the user ask specifically. There is a default one.
- Do not assume how works the CMS if you are not sure. Just use the provided information.

Provide the bullet list in Markdown within <task_details_md> tags.

# 6. Write an explanation

Also, write a short explanation of your choices, within <explanation_md> tags. Write the explanation in markdown and in the language of the update message. Your explanation message will be shown to the end-user as a message in a chat. Don't describe choices when they're obvious. Be as succinct as possible.

Do not include any other explanation or commentary outside these tags.