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

Annotations already declare a safe, read-only, idempotent computation, so the description's job is to add context — and it does: it discloses the return content (amount paid via the notary on deed day, total, itemized entries, first-home comparison) and two important limits (no notary honorarium, full ownership only, not a formal quote).

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?

Front-loaded with the purpose, then inputs, then outputs, then exclusions; every clause carries information and the closing English sentence aids disambiguation. It is dense but not padded, though the enumerated tax list makes it longer than strictly necessary.

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 9-parameter, high-complexity tax calculator with an output schema and full annotation coverage, the description covers purpose, when to use it, required inputs and their conditions, output content, and explicit exclusions. Nothing needed to call it correctly is missing.

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% with richly documented enums, so the baseline is 3. The description goes slightly beyond by naming the conditional input dependency (price always, plus cadastral income when a person buys and the sale is VAT-exempt) and pointing to the visura as the source of rendita catastale.

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 and resource (calculates Italian purchase taxes on a home or pertinenza) and enumerates the exact tax items covered (registro/IVA, ipotecaria, catastale, Archivio notarile, loan tax). It is readily distinguishable from siblings such as imposte_successione_donazione, usufrutto_nuda_proprieta or valore_catastale, which address different tax/valuation scenarios.

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 an explicit trigger: 'Si usa quando una persona chiede quante imposte pagherà comprando', and scopes it to private-vs-company sellers and with/without first-home relief. It also states a boundary (excludes notary fees, is not a quote), though it never names a sibling tool as an alternative for adjacent questions.

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