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

Annotations only declare destructiveHint=false, so the description carries the behavioral load, and it does: creation is instantly visible and reviewed afterwards, hosting is forced to platform-side with hostedEnabled/signupUrl silently discarded and external URLs stripped, and dedup returns the existing activity for the same clientRequestId or same title within 5 minutes. It also discloses that organizer identity comes from the verified organization profile and cannot be changed by the agent. This is exactly the non-obvious behavior an agent needs.

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 content is dense and front-loaded with the purpose, but it is written as a single semicolon-chained block mixing purpose, workflow, constraints, question design, and idempotency with no grouping. Abbreviations such as 外表 and 按exits补 require the reader to infer meaning. It is appropriately sized for a 23-parameter mutation tool but poorly structured.

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 complex create tool with no output schema, it covers preconditions, forced behaviors, follow-up steps, and dedup so an agent can invoke it safely. The gap is the return value: it never says whether the call yields an activity id or draft that later steps need, which matters given the prescribed update_organizer_signup_config follow-up. Nothing else material 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 and the schema already explains deprecated fields and enums. The description adds meaning beyond it: the seven built-in question keys, that extraQuestions are Chinese-only with server-generated key/type and always optional, the organizerName default and co-branding full-name rule, and the 5-minute same-title reuse window. Some of this is duplication, but the question-model and dedup semantics are genuine additions.

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 opening states a concrete verb and resource: create an activity that immediately goes live on the activity feed / signup page with post-hoc review. It distinguishes itself from sibling organizers tools (get_organizer_activity, update_organizer_signup_config) by naming them as the next steps. The core purpose is clear but is buried inside a dense clause chain, which slightly muffles it.

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?

It gives explicit routing: external-form activities must use another entry point, COMPETITION is unsupported, offline events require a location, and complex questionnaires go to /pro. It also prescribes the follow-up flow (get → update_organizer_signup_config → list_signup_submissions → review/export) and the fallback when eligibility or published products are insufficient. It stops short of naming the concrete sibling tool for the external-form and /pro cases.

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