Export an ACF field group as JSON for backup or migration, letting you save its key and settings for later import.
Export a field group in ACF JSON format (for import/backup)
| Name | Required | Description | Default |
|---|---|---|---|
| key | Yes | Field group key | |
| site | Yes | Site id (see list_sites) |
Changes observed during successful MCP inspections.
v3.4.0Input schema / properties / siteAdded value: +{
+ "description": "Site id (see list_sites)",
+ "type": "string"
+}Input schema / requiredPrevious value: -[
- "key"
-]New value: +[
+ "site",
+ "key"
+]v2.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It usefully discloses the export payload format (ACF JSON), which is beyond the schema, but it does not state whether the result is a returned JSON blob or a written file, whether the operation is purely read-only, or what permissions are required.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
A single front-loaded sentence with no filler; the format and purpose are packed into one clause. It is efficient, though nearly too terse to be maximally informative.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a 2-parameter export tool with no annotations and no output schema, the description should clarify the return shape (JSON string vs download file) and any permission requirements. It covers the format but leaves the consumption contract unstated.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 100%, so both 'key' and 'site' are already documented in the schema; the description adds no meaning about either parameter. Baseline 3 applies when the schema does the heavy lifting.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
States a specific verb (export) and resource (field group) plus the output format (ACF JSON). This clearly separates it from the sibling acf_import_field_groups and acf_get_field_group, though it never names those alternatives explicitly.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The parenthetical '(for import/backup)' implies the intended use case, but there is no explicit when-to-use guidance, no prerequisites, and no statement of when to prefer acf_get_field_group or acf_import_field_groups instead.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.