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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds that ETFs are included and flagged via is_etf, which is genuinely useful behavioral context. It says nothing about ambiguity handling (partial name matches, multiple issuers) or rate limits, so a 3 is appropriate.

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, zero filler. The core input→output mapping comes first and the ETF caveat follows as a short trailing note. Each clause carries information.

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 no output schema, the description correctly takes on the burden of stating the return shape (issuer, code, market) plus the is_etf flag. The only gap is behavior on ambiguous or zero-match queries, which an agent might reasonably want before calling.

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%, so the schema already documents both query and limit (including default 10 / max 30). The description adds the meaningful constraint that stock codes are 6 characters and that names may be Korean or English, which is a small increment over the schema. Baseline 3 is right.

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 uses a specific verb ('Resolve') and states exactly what inputs map to what outputs: Korean or English company name or 6-character code → issuer, code, market (KOSPI/KOSDAQ). It also discloses the ETF edge case with the is_etf flag. It does not name a sibling tool, but the resolution role is clearly distinct from quote/history siblings.

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?

Two concrete usage examples ('map a ticker like 005930 to Samsung Electronics', 'find the code for SK hynix') make the when-to-use case unambiguous. There is no guidance on when NOT to use it or which sibling (kr_quote, kr_price_history, company_register_search) to pick instead, 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.