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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so safety is covered without the description's help. The description adds the upstream source (USGS) and the filter dimensions, but says nothing about data latency/refresh, whether results are magnitude-sorted, or the effective default window — useful context still missing.

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?

Two tight sentences, front-loaded with the resource and source, and the filter enumeration is compact. Slightly under-specified rather than bloated, but no sentence is wasted.

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 8 optional parameters, no required fields, no output schema and no sibling differentiation, the description should carry more weight. It omits what "recent" defaults to, how results are ordered or capped, and how this differs from usgs_earthquake_feed/usgs_earthquake_search, while introducing a phantom state filter.

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 coverage is 100%, which normally sets a baseline of 3, but the description advertises a "state name" filter that does not exist as a parameter — the schema exposes only location (address/zip/city/'lat,lon'), lat/lon, radius_km, min_magnitude, start_time, end_time and limit, with additionalProperties=false. That invites an agent to pass a state argument that will fail validation, which is worse than adding nothing.

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 specific resource and source ("Recent earthquakes from USGS") and enumerates filter axes, so the basic purpose is clear. But the sibling list contains usgs_earthquake_feed, usgs_earthquake_search and usgs_earthquake_detail, and the description gives no basis for choosing this tool over those three near-identical neighbors.

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, or alternative routing anywhere. With three other earthquake tools present, an agent has to guess whether "recent" means this one or the feed/search variants, and nothing in the text resolves that.

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