Earthquake statistics

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

Annotations already declare readOnly/idempotent/non-destructive/openWorld, so the description is free to spend its words on data behavior. It does: places are nearest-town/EMSC-region labels with no province data, and `truncated` reveals that counts can silently reflect only the newest events because the source capped at 3000 rows before Iran filtering. That truncation disclosure is exactly the kind of trait annotations cannot convey.

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 scope and output shape come first, then the usage trigger, then two dense caveats. Three sentences, no filler, and every clause carries information an agent cannot get from the schema or annotations.

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 and no annotations on return shape, the description carries the burden and largely meets it: it names the three result components and the truncation flag, and notes source-specific limitations (IRSC only ~20 events). It stops short of describing the exact structure or empty-result behavior, but an agent has enough to call and interpret it.

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%, so the baseline is 3, but the description adds cross-parameter meaning the schema lacks: place values depend on which source is chosen, and `truncated` interacts with the iran_only/source filtering. It clarifies semantics rather than restating 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?

States a specific verb (Count) and resource (earthquakes in Iran) plus the exact aggregations returned: magnitude band, place, and strongest event. The counting/aggregation framing is implicitly distinct from siblings like eq_search or eq_detail, but no sibling is named explicitly, so it falls just short of a 5.

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?

Gives a concrete usage trigger ("how active has Iran been this month"), which maps cleanly onto an activity-summary tool rather than an event-lookup tool. It gives no explicit exclusions or named alternatives (e.g. eq_search for individual events), so it is clear context without routing guidance.

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