Compare Parcels

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

With no annotations, the description carries the full behavioral load and does so well: it discloses country coverage (ES/PT/FR/IT/DE), that area/land use/municipality are populated only for Spain, that no market prices are returned, and that a missing parcel yields an error while the rest still compare. It also notes the whole comparison is one API call. Auth/permission requirements are the only notable omission.

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?

Roughly four compact sentences, front-loaded with what the tool does and what it returns, followed by constraints and edge cases. Every sentence carries information; only the density of the country caveats borders on crowded.

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?

There is no output schema and no annotations, yet the description covers return contents, per-country field availability, unsupported regions, partial-failure behavior, and call cost. An agent has everything needed to call this correctly and interpret the result.

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 baseline is 3. The description goes further by explaining that the country code is semantically tied to regime support (ES common regime) and that the returned fields differ by country, giving the agent context the schema's plain enum list cannot convey.

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?

It states a specific verb (compare) plus resource (parcels) and enumerates exactly what is compared: location, solar potential, agricultural use and investment score. The 2-3 parcel scope and multi-country support immediately separate it from get_parcel and the other single-aspect siblings.

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?

It gives an explicit when-not ('Basque Country and Navarre are not supported here') and routes the agent to the alternative ('use the single-parcel tools'). It also implies the 2-3 parcel minimum. That is strong routing guidance, though it never states positively when comparison beats calling get_parcel per parcel.

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