Retrieve custom field definitions for products, customers, vendors, and orders. Filter by entity type, sort, paginate, and include total counts.
List all custom field definitions
| Name | Required | Description | Default |
|---|---|---|---|
| skip | No | ||
| sort | No | Property to sort by (e.g., name, entityType) | |
| count | No | ||
| sortDesc | No | Sort in descending order | |
| entityType | No | Filter by entity type | |
| includeCount | No | Include total record count in response |
Changes observed during successful MCP inspections.
v1.4.0-alpha.2Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full behavioral burden, yet it discloses nothing beyond that it is a listing operation. It is silent on pagination behavior (skip/count), whether results are paginated or capped, default sort order, and what the definition objects contain. 'List' weakly implies a safe read, but that is the extent of the disclosure.
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?
It is a single efficient sentence with no filler, which is good structure, but the terseness crosses into under-specification rather than genuine conciseness. Nothing is front-loaded because there is only one clause.
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 6-parameter tool with no annotations and no output schema, the definition leaves too much unspecified: pagination semantics, default sorting, and the relationship between entityType and the returned definitions are all unstated. An agent can call it, but cannot call it confidently or correctly on first attempt.
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?
Six parameters exist with only 67% schema description coverage, and the description adds no parameter meaning at all. The undocumented 'skip' and 'count' parameters, which control pagination, are left for the agent to guess, and the description never clarifies that entityType filters the listing.
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?
The description gives a clear verb ('List') and resource ('custom field definitions'), so an agent knows exactly what object it retrieves. It does not, however, distinguish itself from the nearby get_custom_field_dropdown_options or explain how these definitions relate to entity types. Clear but undifferentiated.
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?
There is no when-to-use guidance, no mention of prerequisites, and no routing to alternatives such as get_custom_field_dropdown_options. The agent must infer usage purely from the tool name.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.