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

With no annotations, the description carries the full behavioral burden and does so: quota cost is one unit per unit served with a per-page minimum, a worked example (120 dwellings = 120 units), and the per-finca cap/repeat-page-free rule for Startup/Growth plans. It also discloses a data-shape caveat that foral records carry no participation coefficient.

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 purpose and the return fields are front-loaded, and the pagination and quota sentences each carry distinct operational value. The final cost sentence is long and packs two rules (per-unit cost and per-finca cap waiver), which is dense but not wasteful.

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 what is returned, the truncation/cursor loop, the quota economics, and the country-specific data caveat. An agent has everything needed to call it correctly and to predict its cost.

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, but the description adds real meaning: cursor is tied to the truncated flag flow, and country is explained as defaulting to ES with foral references auto-detectable by shape. The 14-character finca reference format and its origin are reinforced beyond the schema text.

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?

States a specific verb+resource ('Every unit ... of a Spanish building') and enumerates exactly what a unit is (dwelling, shop, garage, storage) plus the fields returned. It also scopes the geography and names search_address as the source of the reference, so it is distinguishable from siblings like get_parcel or resolve_reference.

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?

Gives clear conditions: Spain only, the three valid country codes, where to obtain the reference (e.g. from search_address), and the exact pagination rule (when truncated is true, call again with cursor = next_cursor). It does not state any when-not or point to a sibling that covers non-Spanish or aggregate use cases, which keeps it short of a 5.

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