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 adds the useful behavioral constraint that it never defaults to Paris and requires an explicit location, but says nothing about output format, latency, or failure when a location is ambiguous.

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?

Three very short, front-loaded sentences with essentially no filler. The location-input modes and the no-Paris-default caveat are each one clause, though the sentences are telegraphic enough that clarity is traded for brevity.

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 values need not be explained, and annotations cover the safety profile. What remains missing is the core behavioral contract an agent needs: which days are covered by default, what happens when both city and lat/long are supplied, and how it differs from the weather-recommendation siblings.

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 does add real value by stating the two location modes (Ville/CP OR latitude+longitude), implicitly clarifying that the "location" parameter is an alias of city and that postal codes are accepted — but it says nothing about days or the 1–7 bound.

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?

"Looks matin, midi, soir selon la météo locale" conveys that it produces outfit recommendations for morning/noon/evening based on local weather, but the verb is nominal and implicit. It does not distinguish itself from sibling tools with near-identical framing such as recommend_weather_look or recommend_look, so an agent could not confidently pick this one on purpose alone.

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?

No when-to-use / when-not-to-use guidance and no mention of the obvious alternatives (recommend_weather_look, recommend_look, get_weather_context). The only guidance-like statement is "Je ne suppose jamais Paris," which is a location caveat rather than routing advice.

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