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

Annotations already set readOnlyHint=true and openWorldHint=true, so the description does not need to restate safety. It adds the cost detail ('[호출당 5포인트]') and says a similarity result is returned, but it does not describe the output shape, scale, or whether the pages are fetched server-side. This is acceptable but not rich behavioral context.

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 short and front-loaded with the core purpose in the first English sentence. There is some bilingual redundancy (the Korean sentence restates the English one), but the added use case and cost bracket are useful and keep it compact.

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 read-only tool with annotations, the description covers purpose, use cases, and cost. However, with no output schema, it leaves the exact meaning of 'similarity result' undefined (e.g., numeric score, percentage, label), which an agent may need to interpret the response confidently.

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%: url1 and url2 are each documented as the first/second page URL to compare. The tool description adds only the general concept of page similarity, not new parameter-level meaning, so the schema carries the load and the baseline of 3 applies.

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 states a specific operation ('Compare two web pages and judge how similar they are') with a clear resource (two page URLs), and the Korean phrase '두 사이트 페이지의 유사 여부를 분석' reinforces that it analyzes page similarity. This is distinct from sibling tools like image_similarity, which compare images rather than web pages.

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 gives an explicit use case ('피싱·복제 사이트 판별 등에 활용할 수 있습니다' - can be used to identify phishing/clone sites), which tells an agent when it is appropriate. It does not discuss when not to use it or mention alternatives such as image_similarity, so it stops short of full routing guidance.

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