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

Annotations already declare the safety profile (readOnly, idempotent, openWorld, non-destructive), so the bar is lower. The description adds genuinely useful context beyond them: a concrete cost ($0.002) and a caveat that distances use site reference points and are not a property-safety determination.

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 with zero filler; the resource and scope are front-loaded ahead of the cost and caveat. Every clause earns its place.

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, the description usefully enumerates the returned fields (identifiers, cleanup status, hazard-ranking score, dates, distance, source profiles) and discloses cost and a disclaiming caveat. Only the radius parameter's semantics are left under-explained.

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 only 25%, so the description must compensate, yet it adds little beyond 'coordinates or a place' and an implicit nod to 'distance'. It never explains radius_km units, its default of 10, or its 1-50 bounds, leaving the parameter semantics largely to the schema's min/max.

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 ('Find') and resource ('U.S. EPA National Priorities List sites') with clear scope ('near coordinates or a place'). It even enumerates the returned fields, and no sibling covers the same subject, so an agent can select it without ambiguity.

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?

The description implies the two input modes (coordinates vs a place), which is useful context, but it never states when to prefer this tool over related siblings like get_radon_potential or geocode_address, nor any exclusions. Usage is implied rather than guided.

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