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

Annotations already cover the read-only, idempotent, closed-world safety profile, so the description's job is to add context — and it does: it discloses the 20-result cap, that the registry spans 'every era' including historical comuni, and that each result carries province and validity dates. Only minor gaps remain (no pagination or truncation guidance beyond the cap).

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?

Three tight sentences, front-loaded with the searchable universe and result shape, ending with the date-filter hint. No sentence is filler.

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, so the description carries the return-value burden — and it does, specifying result count cap, fields (province, validity dates), and the record universe. An agent has everything needed to call this 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 description coverage is 100%, so the agent already knows 'q' accepts names or codes and 'date' is an optional YYYY-MM-DD validity filter. The description adds the search domain ('15,000 comuni of every era and foreign states'), which helps but mostly restates the schema's own examples and format hints.

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 (search/lookup) and resource (comuni and foreign states in the ANPR archive) and names the exact identifiers returned (codice catastale such as H501 or Z110). It is clearly distinguishable from the sibling compute/decode/verify codice fiscale tools, which act on tax codes rather than place registries.

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?

Explains the two search modes (by name or by code) and explicitly tells the agent to supply a date to narrow results to places valid on that day. It does not name when to prefer a sibling or any exclusions, but the usage context is clear for a self-contained lookup tool.

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