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

Annotations already declare readOnly/idempotent/non-destructive, so the bar is lower; the description adds genuinely new behavior: a hard top-20 cap and consumption of one trial-quota unit. It does not describe the response shape or pagination, but the quota disclosure is the kind of operational cost an agent needs.

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?

Two sentences, front-loaded with the return content, then the quota cost. No filler. Slightly compressed for a tool whose range semantics (month window) are only conveyed via the schema.

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?

A read-only, closed-world retrieval tool with no output schema; the description covers what is returned (top 20 percentage shares) and the cost, and the schema covers date bounds and the report code. Complete enough to invoke correctly without further prose.

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 coverage is 100%, so code, from, to, and agent are all documented in structured fields with examples and defaults. The description adds no parameter meaning beyond the schema, which is the correct baseline when the schema does the work.

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?

Names a specific verb (돌려줍니다) and resource (전체 업종의 구성비 상위 20개), and enumerates the breakdown dimensions (검색엔진 · AI 플랫폼 · 브라우저 · 운영체제 · 유입 경로). This clearly separates it from get_time_pattern and get_totals, though siblings are never named 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?

Provides a usage-relevant anchor (끝난 월 기준) and a cost signal (맛보기 한도를 1회 씁니다), which an agent can weigh before calling. However, it never states when to prefer this over get_time_pattern, get_totals, or get_industry_brief, so the routing decision stays implicit.

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