Piton de la Fournaise et séismes à La Réunion

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

Annotations already declare readOnly/idempotent/openWorld, so the bar is lower, and the description adds real context: the earthquake window is fixed at the last 30 days, and the payload reflects the latest OVPF publications and the most recent eruption date. It doesn't state refresh cadence or source authority beyond naming OVPF-IPGP, which would have pushed it higher.

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 enumerated scope is front-loaded and each listed field earns its place by telling the agent what comes back. The trailing bilingual restatement is partly redundant with the French text, and the run-on first sentence packs a lot into one clause chain.

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 output schema and no parameters, the description carries the whole burden and does so by enumerating the returned fields plus their temporal scope (30 days of seismicity, last eruption date). An agent knows what it will get and when it applies without opening anything else.

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 the baseline is 4; there is nothing for the description to disambiguate. It correctly signals a single-shot, no-argument call.

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 concrete resource (Piton de la Fournaise volcano status + Réunion earthquakes) and enumerates exactly what it covers: eruption state, ORSEC alert level, last eruption date, Enclos Fouqué access, OVPF publications, and 30-day seismicity. This is clearly distinguishable from weather/air-quality siblings such as meteo_actuelle or vigilance_meteo.

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 example user questions ("le volcan est en éruption ?", "on peut monter au volcan ?", "il y a eu un séisme ?") give a concrete trigger set for when to call it. What's missing is an explicit boundary against the closest siblings — e.g. whether seismic/alert info should ever be sought from vigilance_meteo instead.

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