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

Goes well beyond the annotations (which only say not-readonly, idempotent, non-destructive): it discloses that a REAL account is created under the email, that no money moves, that user_confirmed is enforced, and that channel/member key are server-decided. This is exactly the information an agent needs before committing a write.

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?

Purpose and the critical consent gate are front-loaded, and every sentence earns its place. The bilingual Korean text is a near-verbatim repetition of the English, which adds length without new information, holding it below a 5.

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 registration mutation with five params and no output schema, the description covers the consent prerequisite, the idempotent return behavior, and the server-controlled fields. Nothing an agent needs in order to invoke it correctly is missing.

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, but the description adds genuine meaning: it explains why user_confirmed is mandatory and that anything other than true is rejected, and clarifies that channel/member key are deliberately absent as arguments. It reinforces rather than duplicates the schema.

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+resource ('Register a star365 unified member') and even names the underlying action (action=members.register). This distinguishes it cleanly from read-only siblings like member_lookup and members_summary without opening any schema.

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 clear preconditions: consent must be obtained via the privacy URL before setting user_confirmed=true, and it explains that already-registered people get the existing member back rather than a duplicate. It doesn't explicitly name a sibling alternative (e.g. member_lookup) but the usage context is unambiguous.

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