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

With no annotations, the description carries the transparency burden. It discloses that the tool is free, returns specific fields (magnitude, depth, tsunami flag, felt reports), and supports location-based filtering. It does not mention rate limits or pagination, but covers core behavioral traits.

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 main purpose, and includes a parenthetical about the paid API that is relevant but not excessive. Every sentence earns its place, and there is no wasted text.

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?

The description explains the data source, scope, and return fields (compensating for the lack of an output schema). It does not explicitly describe output format or defaults, but the schema covers defaults, and the tool is a relatively simple read operation. The provided details are adequate for an agent to invoke it correctly.

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 input schema provides 100% coverage with descriptions for all 5 parameters, so the schema does the heavy lifting. The description adds context that 'location' is a named place and that radius applies around it, but does not significantly enhance parameter meaning beyond the schema.

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 identifies the tool as providing recent earthquakes from the USGS feed, with a scope of worldwide or radius around a named place. This distinguishes it from sibling tools like elevation or air_quality, which handle different data domains.

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?

It states the primary use case (retrieving recent earthquake data) and differentiates the free tool from a paid API by pointing to paid_catalogue for routes and prices. It does not explicitly list exclusions or when to use alternative tools, but the context is sufficient.

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