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

With no annotations and no output schema, the description carries the full disclosure burden, but it only adds numeric caps for radius and days. It does not explain read-only behavior, authentication requirements, subscription gating implied by 'PRO.', return format, or rate limits.

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 compact and front-loads the core search scope and constraints. The leading 'PRO.' is cryptic and the fragment style leaves some ambiguity, but there is little wasted text.

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 five-parameter search tool with no annotations and no output schema, the description is too thin: it omits authentication/subscription behavior, return values, and sibling routing. The filter constraints are useful, but an agent would still be guessing about important call behavior.

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 only 20%, so the description meaningfully compensates by clarifying that radius is in kilometers with a max of 1000, days max out at 365, and min_mag is a minimum magnitude filter. It does not clarify the optionality or role of access_token, but that parameter already has a schema description.

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 clearly states a specific resource and scope: earthquakes near a postal code with custom radius, days, and minimum magnitude. It does not explicitly differentiate itself from the sibling recent_quakes, though the customizable proximity filters imply a broader search than a recent-quakes listing.

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?

Usage is implied by the proximity-search scenario and custom filter options, so an agent can infer when this tool is appropriate. However, it never names recent_quakes or sites_check, nor does it explain when to choose this tool over those alternatives.

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