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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description goes further and discloses non-obvious behaviour: fuzzy street matching reported via `interpretazione` (scritto/inteso), fallback `alternative` streets, suggestion output when comune/via are ambiguous, and conditional presence of `buonoOpenFiber`. It does not cover latency or rate limits, but for a read-only lookup this is substantial added context.

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 core capability is front-loaded in the opening sentence, and every subsequent sentence carries distinct information (listino uniformity, ambiguity handling, interpretazione/alternative semantics, buonoOpenFiber). It is a dense single paragraph with several parenthetical asides rather than a cleanly structured block, but 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 does so well, naming the technology, speed, offer, router, recognised address, interpretazione, alternative and buonoOpenFiber. The main gap is the negative case (what happens when no technology is available at the address), which is only implied by the suggestion behaviour.

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 baseline is 3. The description singles out `cliente` and explains the privato/azienda distinction and why it matters for offer eligibility, but this largely restates the enum's schema description. For `via`, `civico` and `comune` it adds nothing beyond the schema.

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 first sentence states a specific verb and resource: it returns which Interfibra technologies (FTTH, FTTC, FWA) can be activated at an Italian address, plus max speed, best offer and router. That is far more specific than a tautology. It stops short of explicitly differentiating from siblings like elenco_offerte or dettaglio_offerta, which also deal with offers, so an agent must infer the boundary.

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 clear (verify coverage for a given address, then advise the client), and the description even prescribes follow-up behaviour: tell the client which street was verified and use an alternative if it is not theirs. It does not state when to reach for a sibling tool instead, so there are no explicit exclusions.

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