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

Annotations already mark the tool as readOnlyHint=true and openWorldHint=true. The description adds that results are not saved and are fetched fresh on every call ('결과는 저장하지 않고 매 호출마다 즉시 조회합니다'), plus a per-call cost of 5 points. This extra information goes beyond the structured annotations.

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 description is bilingual, which adds length, but it is front-loaded with the purpose in the first sentence. Every subsequent sentence adds value: behavior, examples, alternatives, and cost. It stays within a reasonable length given the need for examples and alias guidance.

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 only two parameters and no output schema, the description covers the core usage, examples, alternatives, real-time behavior, and cost. It could mention what the returned status looks like, but for a simple read-only lookup the current level of detail is sufficient.

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?

The schema already provides 100% coverage for both parameters, but the description enhances it with concrete carrier code examples (e.g., cj, hanjin) and points to the full list at /rest/parcel_tracking_carriers, and clarifies that parcel_tracking_auto handles unknown carriers. This adds meaningful guidance on valid parameter values.

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 description opens with 'Track a Korean parcel in real time by carrier code and tracking number,' clearly stating the verb, resource, and required inputs. It also distinguishes from sister tool parcel_tracking_auto by noting that this tool requires a known carrier code.

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?

It explicitly instructs: 'if you don't know the carrier, use the parcel_tracking_auto Tool for automatic identification.' It also points to a free endpoint for the full carrier list, giving clear direction on when to use this tool vs alternatives.

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