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

Beyond the readOnlyHint and openWorldHint annotations, the description states results are not stored ('결과는 저장하지 않고') and each call queries in real time, plus the per-call 5-point cost. These details affect caching, cost, and re-use decisions and are not present in the 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 front-loaded with purpose, then behavioral notes, carrier examples, alternative routing, and cost. The bilingual text causes some duplication, but every sentence carries useful information 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?

For a two-parameter real-time lookup with no output schema, the description is complete: carrier identification, tracking number, alternative tool, cost, and no-persistence behavior are all covered. The lack of a detailed return format is acceptable because the purpose statement clearly indicates the result is delivery status.

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 input schema already documents both parameters with examples, so the basic semantics are covered. The description adds value by giving concrete carrier code examples with Korean names and directing users to a free endpoint for the full list, though it does not specify tracking-number format details.

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,' naming a specific action, object, and required method. It also distinguishes itself from parcel_tracking_auto by requiring a known carrier code, so its role among siblings is clear.

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 tells the agent to use parcel_tracking_auto when the carrier is unknown, and points to /rest/parcel_tracking_carriers for the full carrier list. This is concrete when-to-use and alternative guidance that is not left to inference.

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