US Government Open Data MCP

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

No annotations are provided, so the description carries the full burden. It discloses return data (magnitude, location, depth, etc.) and magnitude scale context, which adds value beyond the input schema. However, it doesn't mention behavioral traits like rate limits, authentication needs, pagination (though 'limit' parameter hints at it), error handling, or whether it's a read-only operation (implied by 'Search' but not explicit).

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 appropriately sized with three sentences: the first states the purpose and key parameters, the second lists return fields, and the third provides magnitude scale context. Each sentence adds value, and it's front-loaded with the core functionality. There's no wasted text, though it could be slightly more structured (e.g., bullet points for returns).

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 no annotations and no output schema, the description provides basic context: purpose, return fields, and magnitude scale. However, for a 10-parameter search tool with complex inputs (e.g., spatial and temporal filters), it lacks details on behavioral aspects like rate limits, error cases, or response format structure. It's minimally adequate but has clear gaps in completeness for such a tool.

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%, so the schema already documents all 10 parameters thoroughly. The description adds marginal value by listing searchable parameters ('magnitude, location, date range, and more') and providing magnitude scale context, but doesn't explain parameter interactions (e.g., that 'maxradiuskm' requires 'latitude'/'longitude') or add syntax details beyond the schema. Baseline 3 is appropriate given high schema coverage.

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's purpose: 'Search for earthquakes by magnitude, location, date range, and more.' It specifies the verb ('Search') and resource ('earthquakes'), and lists key search parameters. However, it doesn't explicitly differentiate from sibling tools like 'usgs_earthquake_count' or 'usgs_significant', though those likely serve different purposes (count-only vs. significant earthquakes).

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 implies usage context by listing searchable parameters (magnitude, location, date range) and providing magnitude scale interpretations (e.g., '2.5+ felt by people'), which helps guide when to use it for earthquake queries. However, it doesn't explicitly state when to use this tool versus alternatives like 'usgs_earthquake_count' (for counts) or 'usgs_significant' (for significant events only), nor does it mention prerequisites or exclusions.

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