lookup_city

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

The readOnlyHint already declares this is a safe read operation, so the description's main job is to add value beyond that. It does so by describing the returned fields (città, CAP, sigla provincia) even though no output schema exists, but says nothing about behavior on no-match, ambiguity, or partial input.

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?

A single compact sentence, front-loaded with the resource and lookup keys, followed by the result and purpose. No redundant wording.

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 two-parameter read-only lookup with no output schema and 0% schema coverage, the description supplies both input roles and the shape of the result. It is nearly complete, lacking only guidance on no-match/ambiguous results or input formats.

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 0%, so the description must carry the load: 'da CAP o nome' maps the CAP to postal_code and 'nome' to city, and signals that either may be supplied (consistent with 0 required parameters). This meaningfully exceeds the bare schema, though it gives no format hints (CAP length, name spelling).

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?

The description names a specific resource (Comuni italiani) and the lookup keys (CAP or nome), and states the returned fields (città, CAP, sigla provincia). It is clear what the tool does, though it does not distinguish itself from the generic 'lookup' or 'client_from_vat' 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?

Usage context is implied by 'necessari per le fatture elettroniche', which tells the agent this is for filling invoice address data. However, there is no explicit when-to-use/when-not or comparison against the sibling 'lookup' or 'client_from_vat' tools.

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