list_fields

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states the action ('List all available fields') but does not describe output format, pagination, sorting, error conditions, or dependencies (e.g., requires a datasource to be loaded). This leaves significant gaps for an agent to understand how the tool behaves in practice.

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?

The description is a single, efficient sentence that directly states the tool's purpose without any fluff. It is front-loaded with the core action and resource, making it easy to parse. Every word earns its place, adhering to ideal conciseness standards.

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?

Given the tool has 0 parameters, 100% schema coverage, and an output schema exists, the description is minimally adequate. However, it lacks context about behavioral aspects (e.g., what 'available fields' includes, error handling), which would help an agent use it correctly. The output schema mitigates some gaps, but the description could be more informative for a tool in a complex environment like workbook management.

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?

The tool has 0 parameters, and schema description coverage is 100%, so no parameter documentation is needed. The description appropriately does not discuss parameters, focusing instead on the tool's purpose. A baseline of 4 is applied as it avoids unnecessary details while being complete for a parameterless tool.

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 clearly states the verb ('List') and resource ('all available fields in the current workbook datasource'), making the purpose specific and unambiguous. It distinguishes itself from siblings like 'list_dashboards' or 'list_worksheets' by focusing on fields within a datasource, not other workbook components.

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 description provides no guidance on when to use this tool versus alternatives. It does not mention prerequisites (e.g., needing an open workbook), exclusions, or related tools like 'profile_data_source' or 'inspect_target_schema' that might overlap in functionality. Usage is implied but not explicitly defined.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.