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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds a genuinely useful behavioral fact beyond them: '[호출당 20포인트]', a per-call cost of 20 points, which an agent needs for budgeting. It does not cover failure modes for out-of-range coordinates, so it stops short of 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?

Front-loaded with the conversion and its outputs, then the use case and the cost tag; nothing is buried. The English and Korean sentences carry near-identical content, which is mild redundancy, but it is short and every element (outputs, use case, cost) 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 compensates by enumerating the returned fields (jibun/road address, postal code, legal and administrative dong codes), plus cost and a usage scenario. For a single read-only conversion call with fully documented parameters, this is close to complete; only edge-case behavior for invalid coordinates is unaddressed.

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 x, y, and point are each documented with ranges and the mutual-exclusivity note ('point 를 쓰지 않을 때 필요합니다'). The description adds no coordinate syntax or precedence detail beyond that, so the baseline 3 is appropriate.

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+resource pair (좌표→주소·행정구역) and enumerates the concrete outputs: jibun and road addresses, postal code, and legal/administrative dong codes. The coordinate-to-address direction is clear enough to separate it from address-input siblings like geo_address_search, though it never names an alternative 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 고른 지점의 주소와 행정구역을 바로 확인할 때 씁니다' gives a real usage scenario (checking the address of a map-picked point), which is more than pure implication. However, it offers no when-not guidance and does not distinguish this single-point tool from geo_batch_geocode or geo_standardize, leaving the agent to infer the choice.

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