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

Annotations already establish readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds a genuinely non-annotated behavioral fact: a per-call cost of 10 points ('[호출당 10포인트]'), which matters for agent budgeting. It still says nothing about error behavior or coordinate-system assumptions, keeping it below 5.

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 definition is short and front-loaded, leading with the computed outputs before the usage hint and cost note. The Korean line largely mirrors the English sentence, which is some duplication, but for a bilingual tool it is defensible and nothing is wasted.

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 carries the return-value burden and does so by listing every computed quantity (distances, bearings, length, area, perimeter, centroid, bounding box). Combined with a fully documented 4-parameter schema and read-only annotations, an agent has what it needs; only error handling and coordinate-system expectations are unstated.

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 the baseline is 3: mode, unit, matrix and coordinates are all documented in the schema with enum values and the 200-coordinate cap. The description's enumeration of outputs loosely maps to the path/polygon modes but adds no syntax, default, 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?

The first sentence gives a precise verb (measure) plus the exact resource set (segment distances, bearings, total length, polygon area, perimeter, centroid, bounding box) from a coordinate list. An agent can immediately tell this is a geometric measurement tool rather than a geocoder or address tool. It stops short of naming a sibling such as geo_geojson_analyze to draw the boundary explicitly.

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 Korean sentence '지도에서 그린 경로나 필지 좌표를 바로 측량할 때 씁니다' gives concrete scenarios (a path drawn on a map, parcel coordinates) that select this tool. It is clear context but offers no explicit exclusions or named alternatives, so it does not reach the top tier.

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