Lists available data merge fields from a document's current data source so you can identify fields to insert into an Adobe InDesign data merge.
List available data merge fields from the current data source
| Name | Required | Description | Default |
|---|---|---|---|
| document_id | No | Which open document to act on: a name (see document_listOpen) or a 0-based index. Defaults to the front document. |
Changes observed during successful MCP inspections.
v1.6.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations, so the description carries the burden. It signals a read of the 'current data source', implying a data source must be selected, but does not state what happens if none is set or what the listing returns.
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?
One front-loaded sentence with no waste. Appropriately sized for a simple listing tool.
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?
A simple 1-optional-param read tool with no output schema; the description covers the core operation but omits the dependency on a selected data source and the shape of the returned field list.
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 coverage is 100% for the single document_id parameter, and the schema describes it richly (name or 0-based index, defaults to front document). The description adds no parameter detail, so baseline 3 applies.
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?
Specific verb (List) plus resource (data merge fields) and scope (from the current data source). An agent can distinguish it from dataMerge_selectDataSource and dataMerge_mergeRecords, though the description does not name those siblings 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?
Usage is only implied: you would call this after a data source exists to see available fields. No explicit when-to-use, prerequisites, or named alternatives are given.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.