Électricité à La Réunion en ce moment

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

Annotations already cover safety (readOnlyHint, idempotentHint, openWorldHint), so the description's added context is what counts: it discloses the upstream data source (EDF), refresh cadence (every 5 min), geographic constraint (Réunion only), and that the payload spans both live production and a forward-looking grid signal. It does not describe the response shape, but no output schema exists so that gap is small.

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?

Content is front-loaded: what the data is, then the fields, then the forecast component, then use cases. The French/English duplication roughly doubles length, which is defensible for a bilingual catalog but is still repeated rather than additive; a shorter English gloss would have sufficed.

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 parameters and no output schema, the description carries the burden of explaining what comes back, and it does: production total, per-source shares, renewable share, refresh interval, plus the coming-days grid outlook. An agent knows what it will get and whether it fits the user's question before calling.

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 zero parameters, so there is nothing for the description to disambiguate and the baseline of 4 applies. The description correctly implies a no-argument, snapshot-style call rather than suggesting any filtering options.

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 precise resource and scope: real-time electricity production mix for Réunion Island (974), sourced from EDF, broken into per-filière shares plus renewable share and EDF's grid signal for the coming days. It is immediately distinguishable from every sibling (weather, air quality, volcano/seismic), none of which touch energy data.

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?

The 'Pour :' / example-question list ('d'où vient l'électricité ?', 'quelle part de renouvelable ?', 'quand recharger ma voiture ?', 'risque de délestage ?') gives concrete triggers for selecting this tool. It does not state exclusions or name alternatives, but no sibling overlaps, so the practical guidance is clear and complete enough.

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