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

Annotations already declare the tool read-only and idempotent, lowering the burden on the description. The description adds meaningful behavioral context by disclosing that results include per-component units, source release files, missing-year evidence, provenance, and caveats, and by restricting output to final national annual summaries.

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: purpose, output characteristics, example usage, and a scope limitation all appear in efficient sentences. Every sentence earns its place without redundancy.

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 no output schema, the description sufficiently describes what is returned (component values with units, source release file, missing-year evidence, provenance, caveats) and the acceptable input scope. Combined with the exhaustive parameter schema and annotations, an agent has enough to select and invoke the tool correctly.

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%, so the input schema fully documents crop, years, crop_class, and response_format. The description reinforces constraints like '2–7 requested crop years' and 'one crop/class', but does not add significant meaning beyond the schema; the examples provide minor clarification.

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 verb ('Compare'), a precise resource ('2–7 requested crop years across every hosted area, yield, and production metric for one USDA NASS crop/class'), and the limiting scope ('Final national annual summaries only'). This clearly separates it from the other USDA NASS siblings, which focus on history, trends, evidence packs, or series search.

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 explicit example prompts ('compare 2019 and 2025 corn', '2020 vs 2025 soybean acres and yield') and a scope guardrail ('Final national annual summaries only'). It does not explicitly name alternative tools or state when not to use them, but the examples and scope make the intended use case clear.

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