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

Beyond the annotations, the description discloses critical behavioral traits: login is required, the submission is real and immediately visible to admins, the caller must obtain explicit user consent before invoking, and the idempotent short-circuit returns the existing record rather than new progress. It also explains that invitationToken grants pre-approval and instant membership. This is far beyond what readOnlyHint/destructiveHint/idempotentHint provide.

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 dense but well-structured with labeled sections (【需要登录】【组合链】【口径/坑】) and numbered pitfalls. Every sentence carries operational value, and the most critical item—user consent before calling—is front-loaded. No filler is present.

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?

Although there is no output schema, the description covers the full workflow: how to retrieve terms and form fields, what response states mean (joined=true vs pendingReview=true), how to proceed next with submit_signup, and the idempotency caveat. It is complete enough for an agent to select and invoke the tool correctly.

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 only 20%, but the description compensates thoroughly: termsVersionId must equal currentTerms.id, acceptTerms must be true and should be omitted entirely when there are no terms, invitationToken is 43 characters and implies pre-approval, and answers keys must come from formFields[].key. This adds decisive meaning to otherwise undocumented parameters.

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 opens with a specific verb and resource: applying to join an organization on the user's behalf ('以用户本人名义申请加入'), and immediately clarifies that it is a real submission visible to admins. This distinguishes it from admin-side review tools like bulk_review_organization_applications.

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 provides an explicit combination chain (get_organization → this tool → submit_signup) and clear conditions for when to call it, including the prerequisite of reading terms and form fields. It also gives a when-not-to-treat-as-success case: if the user is already a member or has a PENDING application, the server short-circuits. It stops short of naming explicit sibling alternatives, so a 4 is appropriate.

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