login_status

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

Annotations provide readOnlyHint=true, and the description adds important behavioral details: it explicitly states that keys and cookies are never returned, which is critical security context. It also discloses the return fields (authenticated, message) and the behavior on missing/expired sessions. This goes beyond the annotation and gives the agent a clear picture of what the tool does and does not expose.

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 concise and front-loaded: the purpose is stated first, then returns, then behavioral notes. It uses both Korean and English but is not verbose. Every sentence earns its place, and there is no redundant fluff.

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 parameterless, read-only tool with an output schema, the description is complete. It states the purpose, the return structure, the edge-case behavior (missing/expired session), and a security guarantee. An agent has everything needed to call it correctly and interpret the result.

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 tool has zero parameters, so the schema covers 100% (empty). According to the rubric, baseline for 0 params is 4. The description does not need to elaborate on parameters, and it doesn't. It appropriately focuses on behavior and returns.

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 clearly states the tool's function: checking the validity of a saved portal session. It uses a specific verb ('확인' / 'Check') and a specific resource (portal login). It is distinct from siblings like search, fetch, or download, which perform different operations. The purpose is unambiguous.

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 implies when to use this tool (to verify login status before performing other operations) but does not explicitly state when not to use it or mention alternatives. The line about guiding to login if session is missing/expired hints at usage context, but there is no explicit comparison with sibling tools. Given the tool's self-contained nature, this is adequate but not exemplary.

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