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

Annotations already establish read-only, non-destructive, open-world behavior. The description adds useful context beyond annotations: the USGS real-time source, the 30-day maximum window, and the returned fields including tsunami flag and impact alert. It does not cover rate limits or auth, but those are less critical for a public read-only catalog.

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 front-loaded with the core purpose, followed by practical usage triggers and compact examples. Every sentence contributes useful information without unnecessary repetition.

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, the description appropriately lists the key returned fields. It also covers source, time window, and location filtering. Minor omissions such as pagination behavior or response shape details are acceptable given the schema's high coverage and the tool's straightforward read-only nature.

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 description coverage is 88%, so the input schema does most of the parameter documentation. The description reinforces that place and coordinates are optional alternatives and provides example invocations, but it adds little semantic detail beyond the schema's own parameter descriptions.

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 a specific verb and resource: retrieves recent earthquakes from the USGS real-time catalog. It specifies scope, time window, returned fields, and optional geographic filtering, leaving no ambiguity about what the tool does.

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 when' line gives concrete example queries such as 'earthquakes today' and 'was there an earthquake in Tokyo?', making the intended context clear. It does not name exclusions or alternatives, but there are no sibling tools, so this is adequate.

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