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

Annotations already establish readOnly, idempotent, and non-destructive behavior, so the bar is lower. The description adds source (USGS) and recency scope, but does not disclose output shape, ordering, or limits beyond what the schema's parameter descriptions already state. No contradiction with annotations.

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 immediately names the source and then lists the filter dimensions in compact form. It is efficiently sized, though it packs the slightly ambiguous 'state name' phrase into an otherwise tight summary.

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 read-only query tool, the description plus schema defaults and annotations provide a workable picture. However, without an output schema the description does not mention what a result contains or how events are ordered, and no guidance differentiates this from the USGS feed/search 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 descriptions cover 6 of 8 parameters, and the description adds semantic grouping: lat/lon + radius_km, magnitude threshold = min_magnitude, time window = start/end_time. However, 'state name' is not a dedicated parameter and relies on the flexible 'location' parameter, which could mislead an agent looking for a state field.

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?

States a clear resource (recent USGS earthquakes) and enumerates the main filtering dimensions (region, state, magnitude, time). It is not a tautology and gives enough to distinguish from generic search tools, though it does not explicitly contrast with sibling tools like usgs_earthquake_feed or usgs_earthquake_search.

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 use case is implied by the word 'recent' and the listed filters, but the description gives no explicit when-to-use vs alternatives. An agent must infer from sibling names (feed/search/detail) which tool to pick, so there is clear context but no exclusion or routing guidance.

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