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

Annotations already declare readOnly, openWorld, idempotent, and non-destructive, so the safety profile is covered. The description adds little beyond that — no mention of defaults (limit 25, radius 5 miles), result ordering, or pagination behavior, which for an open-world search with 8 params would be genuinely useful.

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 the core purpose front-loaded and zero padding. The audience sentence is the only part that does not fully earn its place, keeping this just short of a 5.

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 100% schema coverage and rich annotations, the description need not restate parameter mechanics. It conveys the domain (alternative fuel types) and spatial intent adequately; the only real omission is the location-vs-coordinates requirement and default radius/limit, which the schema covers.

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 100%, so all 8 parameters are already documented; baseline is therefore 3. The description lists human-readable fuel names (electric, CNG, hydrogen, propane) that loosely map to the fuel_type codes but adds no syntax or format detail beyond the schema.

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 ('Find alternative fuel stations') with a clear spatial scope ('near a location') and enumerates the fuel types covered. It does not, however, differentiate itself from the sibling nrel_alt_fuel_station_detail, so an agent cannot tell where this search tool ends and the detail tool begins.

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 second sentence names intended audiences (route planning agents, fleet operators, EV/clean-fuel tech), which implies a use context but gives no explicit when-to-use, when-not-to-use, or named alternative. It never states that either location or lat+lon is required to make a call, a condition the schema alone carries.

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