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

Annotations already establish this as read-only, open-world, idempotent, and non-destructive. The description adds useful behavioral context beyond those flags: the data is a pre-collected catalogue of earthquake events, and the tool supports proximity claims, not causal damage or shortage claims.

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 sentence communicates the core action and then the most important interpretive caveat. There is no filler or redundant restatement of the schema.

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 simple three-field tool with strong safety annotations, the core call path is clear and no output schema exists to repay. However, the description omits the optional radius semantics and any hint of result limits or ordering, leaving a modest gap for correct invocation in non-default cases.

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%, so the description must compensate, but it only gestures at latitude/longitude with 'caller-supplied coordinates.' It does not explain radius_km, its units, default behavior, or how it shapes the search.

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 first clause states a specific action ('Find ... earthquake events') on a specific resource ('collected earthquake events') near caller-supplied coordinates. This is distinct from all sibling tools, and the caveat reinforces that the tool's output is proximity information only.

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?

It clearly frames when the tool is relevant: whenever earthquake events near given coordinates are needed. It also adds a valuable exclusion—proximity alone should not be treated as evidence of factory damage or product shortage—though it does not name an alternative tool to use instead.

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