Recent significant earthquakes

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

Without annotations, the description explains the USGS significance score (magnitude, felt reports, estimated impact) and mentions the threshold matches the official feed. This adds valuable behavioral context beyond a simple listing. However, it omits any mention of the response format or pagination.

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 core purpose, and contains no unnecessary words. It earns its length.

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 tool's simplicity (2 parameters, no output schema), the description adequately covers the purpose and filtering logic. It lacks details about return format or sort order, but these are less critical for a list tool with clear parameter constraints.

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% with both parameters described. The description adds no new parameter-specific details beyond what the schema already provides. Baseline 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 explicitly states it lists significant earthquakes from the last N days worldwide, using the USGS significance score. It clearly distinguishes from siblings like search_earthquakes or get_earthquake by focusing on a predefined 'significant' threshold.

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 for retrieving notable earthquakes but does not specify when to use this tool versus alternatives (e.g., search_earthquakes for custom filters, count_earthquakes for totals). No exclusions or prerequisites are mentioned.

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