usgs_significant

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

Annotations already provide readOnlyHint=true, and the description adds useful context beyond that: the 30-day fixed window, the 'typically M4.5+ or felt/damaging' selection criteria, and worldwide scope. It does not mention return format or pagination, but for a simple read-only list tool this is acceptable.

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 description is two sentences, front-loaded with the primary purpose and followed by a concise qualifier about magnitude. No filler words; every phrase earns its place.

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?

For a parameterless, read-only tool with no output schema, the description covers the key context: time window, magnitude threshold, and scope. It could go further by specifying the return format (e.g., list of earthquakes with location/magnitude), but the essential decision-making information is present.

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 has zero parameters, so schema description coverage is 100% by default. Per the rubric, a baseline of 4 applies. The description adds no parameter-specific details because none exist; it correctly describes a fixed behavior rather than parameterizable 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 clearly states the action ('Get'), the resource ('significant earthquakes'), and the time window ('past 30 days'), with a specific magnitude threshold ('typically M4.5+ or felt/damaging events'). It distinguishes this from sibling tools like usgs_earthquakes by emphasizing 'significant' and 'notable' events.

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 description implies when to use this tool ('Quick way to see the latest notable seismic activity') and sets expectations with the magnitude threshold. However, it does not explicitly name alternatives or state when NOT to use it, leaving some ambiguity versus sibling tools like usgs_earthquakes.

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