list_variables

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

No annotations are provided, so the description carries the full burden. It clearly indicates a read-only listing operation and discloses the return format as a JSON string with variable names, shapes, dtypes, and units. It does not discuss error handling or file-access details, but that is acceptable for this simple tool.

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 compact and front-loaded with the core purpose. The Args and Returns sections are useful and contain no filler or redundant information.

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 tool with one simple parameter and an output schema, the description adequately covers the input and the return content. It lacks sibling differentiation, but that gap is more relevant to usage guidelines than to overall completeness.

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 0%, but the only parameter is self-explanatory. The description adds that file_path is a path to a NetCDF file, which is marginally more specific than the schema's 'File Path' title, but it does not provide format constraints or other meaningful semantics.

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 states a specific action ('List all data variables'), a clear resource ('NetCDF file'), and the exact metadata returned (shapes, dtypes, units). This distinguishes it from sibling tools like get_variable_info, which focuses on a single variable.

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 about when to use this tool versus alternatives such as get_file_structure or get_variable_info. It also does not mention any exclusions or preferred scenarios, leaving the agent to infer usage context.

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