USGS earthquakes near the Philippines

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

Annotations already declare readOnly, openWorld, and idempotent, so the bar is lower. The description adds valuable context: bounding box coordinates, USGS data source, magnitude types (Mww/Mwc), and depth solutions. This goes beyond basic annotations, though it does not address potential data gaps or latency, which openWorldHint partially covers.

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, followed by scoping and relational details. Every sentence earns its place with no redundancy or filler.

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?

Given the rich schema (100% parameter coverage), existing output schema, and strong annotations, the description fully covers the tool's scope, source, and differentiation. It is complete for a read-only query tool, and no critical context is missing.

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 100%, and all parameters (limit, start_date, end_date, min_magnitude) are well-described in the schema with defaults and meanings. The tool description does not add parameter-specific details, so the baseline of 3 is appropriate.

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 tool returns Philippine-region earthquakes from USGS, with a specific bounding box and cross-reference to PHIVOLCS, including international-standard magnitudes. This distinguishes it from sibling tools like get_earthquake_bulletin and get_latest_earthquakes by emphasizing its global-network analysis and USGS sourcing.

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 provides clear context on when to use the tool: when you need USGS cataloged events with international-standard magnitudes, complementing PHIVOLCS data. It implies a distinction from PHIVOLCS-based tools but does not explicitly name alternatives or provide when-not-to-use guidance.

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