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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the description's added value is telling the agent what comes back (valore in euro plus the conto) and, importantly, what it is NOT (not market value, not IMU value) and where it declines to apply. That boundary disclosure is genuinely useful; it stops short of richer detail like rounding or rate assumptions.

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?

Dense but front-loaded: purpose first, then usage, then what it returns and what it excludes, with an English gloss at the end. Every sentence earns its place, though the text is on the long side and the bilingual repetition adds length.

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?

An output schema exists, so return-value detail is not required in the description, yet it still summarizes the output (euro value plus the calculation) and enumerates the non-applicable cases. Combined with the rich schema and annotations, an agent has everything needed to invoke it 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% and each parameter has a thorough description with enum semantics, so the schema carries the burden. The description adds only the note that casa and pertinenze have separate rendite and that la rendita is found in the visura catastale, which the schema largely already states. Baseline 3 is appropriate.

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?

Starts with a specific verb+resource: calcola il valore catastale di una casa o pertinenza dalla rendita catastale, and frames what it is (tax base under prezzo-valore). It explicitly names siblings it is not (imposte_acquisto_casa, imposte_successione_donazione), so an agent can route without opening schemas.

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?

States the trigger clearly (the person knows the rendita and asks for the cadastral value), covers a second use case (deriving cadastral value for immobili that imposte_successione_donazione requests), and gives explicit exclusions: uffici, negozi, capannoni, terreni, company purchases. It also routes the acquisition-tax question to imposte_acquisto_casa.

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