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

No annotations exist, so the description carries the full burden, and it does well: it discloses the return value (access_token), the required auth header form (Authorization: Bearer), and the exact downstream endpoint including the '?guest 없이' distinction. It omits failure behavior, token lifetime, and whether client_name affects the resulting account, keeping it short of a 5.

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 short sentences, front-loaded with the step position and outcome, then the follow-up call. The parenthetical '(?guest 없이)' is terse but functional; nothing is filler.

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 annotations and no output schema, the description must cover the return and side effects, and it does explain the token and next call. But for a credential-issuing tool it says nothing about code expiry, retry/failure semantics, or the meaning of client_name, so an agent cannot handle error paths from the description alone.

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 only 33% and the description compensates only partially: it clarifies that 'code' is the 6-digit code the user reads aloud, going slightly beyond the schema's '메일로 받은 6자리 숫자'. The 'email' and especially 'client_name' parameters get no explanation in either the schema or the description, leaving a third of the inputs undocumented.

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 (signup/login completion) and the concrete outcome (access_token) for the email_code flow, positioning itself as the final step. This distinguishes it from siblings start_signup and check_signup, though those siblings are not 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?

Clears the key precondition: it is the last step of the email_code method, invoked with the 6-digit code the user has read out — implicitly after start_signup. It also tells the agent exactly what to do afterwards (call the member MCP with the token), though it never states what to do on a wrong/expired code or how it differs from check_signup.

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