Latest earthquakes

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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so safety is covered. The description adds behavior the annotations cannot: results are ordered newest-first, and returned timestamps appear in both UTC and Tehran time (UTC+03:30). It does not discuss rate limits or freshness/latency of the upstream feeds.

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?

Two tight sentences, front-loaded with purpose and scenario, followed by field conventions and sibling routing in one line. No filler and nothing repeated 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 five optional params all fully documented in the schema and no output schema, the description usefully compensates by naming the returned fields (time_utc, time_tehran, depth_km, mag_type) and the result ordering. An agent has everything needed to call it and interpret the response.

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%, including enum, ranges and defaults (limit capped at 50 to stay under 15 KB, source ids not interchangeable), so the schema carries the input burden. The description's extra detail (time_utc/time_tehran, depth_km, mag_type) describes output fields rather than adding meaning to the five input parameters, so the baseline 3 applies.

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 and resource with scope and ordering: "List the most recent earthquakes in Iran, newest first." That clearly separates it from eq_detail (single event) and eq_stats (counts), which the description also names. It never distinguishes itself from eq_search or eq_significant, so it falls short of full sibling differentiation.

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 triggering scenario ("was there an earthquake today?") and routes to alternatives by function: eq_detail for more on an id, eq_stats for counts. There is no explicit when-not guidance (e.g., non-Iran queries or historical ranges belong elsewhere), so it is clear context without exclusions.

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