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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the description's added value is its disclosure of behavior beyond that: results are hard-capped at the top 5, sorted by price, sourced from the Opinet API, and radius is bounded at 5000m. It stops short of describing error behavior or what happens when fewer than 5 stations exist.

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?

Front-loaded with the core purpose, then organized into Args and Returns sections that are easy to scan. The only slight padding is the vendor name 'Fuel Station Compass(주유소 나침반)' and a redundant restatement of the sort order already implied by 'cheapest'.

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 correctly compensates by documenting the return shape (location plus an array of stations with name, brand, price, distance). Combined with the fully documented parameters and annotations, an agent has everything needed to invoke and interpret this tool.

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 carry parameter meaning and it does: location is given with concrete example formats, fuel_type enumerates all four codes with the default (B027 Gasoline), and radius specifies units, maximum (5000m) and default (1000m). Nothing about the parameters is left ambiguous.

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 (finds) and resource (the 5 cheapest gas stations) with clear scope: near a specified location, within a radius. An agent can immediately tell what it returns. It does not explicitly differentiate itself from the sibling find_cheapest_gas_stations_on_route, relying on the name and the phrase 'near a specific location' to imply the distinction.

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 never states when to prefer this tool over find_cheapest_gas_stations_on_route or get_route, nor any prerequisites or exclusions. Usage is only implied by the tool name and the 'near a specific location' phrasing.

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

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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds genuine behavioral context beyond that: the route is sampled, a 1km radius search is run per sample point, and results are capped at the top 5 cheapest. It lacks detail on rate limits or sampling granularity.

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?

Front-loaded with the core action and scope in the first sentence, then args and returns. The structure is clean and each line carries content, though the Args/Returns framing is slightly verbose for a four-parameter tool.

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?

No output schema exists, yet the description spells out the return shape (route_info with distance_km/duration_min, and gas_stations with name/brand/price/distance), and all four parameters plus the sampling behavior are documented. An agent has everything needed to call and interpret the result.

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 carry the parameter burden, and it does: origin/destination with examples, fuel_type with the actual code values (B027, D047, K015, C004) mapped to fuel names, and priority with its three allowed values and default. This is information the schema does not encode.

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 (finds cheapest gas stations) plus a scope qualifier ('along a route') that separates it from the sibling find_cheapest_gas_stations_nearby. An agent can distinguish it from get_route as well, since the returned entity is stations, not a route.

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 name and scope – use this when you have an origin and destination and want stations along the path – but there is no explicit when-to-use/when-not guidance and the sibling find_cheapest_gas_stations_nearby is never mentioned, even though choosing between the two is the main routing decision.

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

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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds genuine behavioral context beyond that: it discloses the external dependency (Kakao Mobility API) and enumerates the returned fields, which is more than the annotations provide. Minor tension: it describes an external API call while annotations set openWorldHint=false.

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?

Front-loaded with a one-line purpose, then Args/Returns blocks that are easy to scan. The Returns block is justified because there is no output schema, though the prose is slightly padded ('using Fuel Station Compass', parenthetical examples) relative to its information content.

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 Returns section correctly documents distance, duration, toll, taxi fare, and resolved origin/destination. Inputs are fully covered. The only real gap is the absence of any routing guidance relative to sibling tools, which is a usage concern rather than a completeness-of-call concern.

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 0% and the schema has no enums, so the description carries the full burden — and it does: it documents all three parameters, gives concrete address/place-name examples for origin and destination, and supplies the RECOMMEND | TIME | DISTANCE value set plus the default that the schema omits entirely.

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 (Retrieves) and resource (route information between origin and destination), names the upstream service (Kakao Mobility API) and the branded surface (Fuel Station Compass). This clearly separates it from the two sibling gas-station search tools, which find stations rather than compute routes.

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 says what the tool does but never says when to choose it over the siblings, nor that find_cheapest_gas_stations_on_route is the natural follow-up to a route it returns. There are no prerequisites, exclusions, or alternative-routing guidance.

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