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

Annotations already declare read-only, idempotent, non-destructive, closed-world. Beyond that, the description discloses real behavior: results are filtered to services that publicly opted in, and supplying a slug re-ranks toward complementary rather than competing services. That ranking/filtering logic is not recoverable from 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?

Three dense sentences with no filler; the opt-in constraint, the slug behavior, and the use cases each carry distinct information. Minor: the lead 'saaskr 한국 SaaS 디렉토리:' is background framing before the actual purpose verb.

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?

All four params are optional and fully documented in the schema, and the description covers the tool's distinctive filtering and ranking semantics. No output schema exists, so return-shape detail is not owed. Adequate for a read-only discovery tool.

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 the baseline is 3. The description adds real meaning for slug — it is the caller's own service and it changes ranking to favor complementary (different-domain, integrable) partners — which the schema only labels as 'the reference service's slug'.

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 (찾는다/find) and a sharply scoped resource: Korean SaaS that have explicitly opted in to partnership proposals. The scope qualifier '직접 밝힌' (explicitly declared) distinguishes it from a generic search or from find_agent_ready_korean_saas.

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?

Gives concrete usage triggers in quotes ('우리 서비스랑 제휴할 국내 서비스', '연동 파트너 찾기') and explains the slug-driven mode, which tells the agent when this tool fits. No explicit when-not or named alternative sibling, so it stops short of 5.

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