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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely new behavioral context: this returns coverage metadata including OCR quality and negative results (years with no pages), and it warns that absence of results is not absence of material.

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?

Two sentences: the first front-loads what the tool returns, the second supplies the decision rule. Dense but each sentence earns its place; only the list-style enumeration of return fields is slightly long-winded.

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?

With an output schema present, return-format detail is unnecessary, and the annotations cover the safety profile. However, for a tool whose three filter arguments are entirely undocumented, the description leaves an agent unable to construct a filtered call with confidence.

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 0% and the three parameters (al, dal, testata) carry no descriptions. The description hints at periodicals via 'testate' and at years via 'anno per anno', but never explains that dal/al are a date range or what format testata expects, so it fails to compensate for the coverage gap.

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 the resource (archivio) and its scope precisely — per-year and per-periodical coverage — and enumerates what it reports (pagine, fascicoli, testate, OCR quality, missing years). This is well beyond a tautology, though it never explicitly contrasts itself with the adjacent archive_info or list_periodicals.

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?

It gives a concrete decision rule: use it to check whether a period is covered before drawing conclusions from a search that returned many or few hits, since silence may be an archive gap. No alternative tool is named for the case where coverage turns out to be sufficient, so it stops short of full routing guidance.

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