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

Annotations already establish readOnly=true, openWorld=true, destructive=false, so the safety profile is covered. The description adds only data provenance (USGS) and says nothing about result ordering, freshness/lag of the upstream feed, empty-result behavior, or whether the non-idempotent hint means results shift as new quakes are recorded.

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?

A single front-loaded clause with no filler; source and filter axes come first. It is efficient, though the terseness is part of why parameter and behavioral detail is missing.

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?

For a tool taking seven required numeric parameters with no schema descriptions and no output schema, one sentence is not enough. The agent cannot tell coordinate order, magnitude scale, epoch units, or a sane limit value from the definition alone.

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 0% for seven required parameters, so the description must carry the burden. 'By magnitude, area and time' hints at the min_mag / bounding-box / since_unix grouping but gives no units, conventions, or bound relationships, and 'limit' is not mentioned at all.

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?

Names a specific resource (earthquakes), the upstream source (USGS), and the three filter axes (magnitude, area, time). It is distinguishable from the cell_sensor_* siblings since none of them deal with seismic data, but it never states that distinction or the tool's relationship to the family.

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?

No when-to-use, when-not-to-use, or alternative is given. An agent must infer that this is a query-only, externally-sourced feed and that the *_at variants in the sibling list are unrelated real-time streams.

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