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

Annotations already cover safety (readOnlyHint=true, destructiveHint=false) and scope (openWorldHint=false), so the description's job is to say what comes back — and it does, listing each returned metric plus the Cadena Láser extended-forecast link. It does not say whether the forecast is cached or how fresh it is, which leaves a small gap.

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 front-loaded sentence that puts the location first and the returned data second; every clause describes a distinct output field. The parenthetical English gloss is mildly redundant but harmless, and nothing else could be cut without losing return-value detail.

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 no input parameters and no output schema, the description must carry the return-value burden itself, and it does so field by field. The only omission is output format/units (Celsius vs Fahrenheit) and data recency, which an agent would only discover by calling it.

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?

The tool takes no parameters, so the baseline is 4. The description correctly spends no space on inputs and instead clarifies that the output is pre-scoped to Río Tercero, which is the only semantic detail an agent needs here.

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 states a concrete resource and scope: weather for Río Tercero, Córdoba, enumerating exactly what is returned (today's high/low, rain probability, current temperature and wind, coming days, plus an extended-forecast link). This is unmistakably different from the news/social siblings (buscar_noticias, radios, resumen_whatsapp), so an agent can select it without opening the schema.

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 is implied rather than stated: the fixed locality and the enumerated data points make the intent obvious, but there is no explicit 'use this when…' guidance and no exclusions (e.g., what to do for another city, or that it cannot be re-targeted). Adequate for a zero-parameter tool, but not directive.

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