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

Adds real behavioral context beyond the annotations: login/organizer requirement, that no phone numbers are exposed, and the important guard that the Agent must not record SMS as sent (preventing hallucinated actions). It does not, however, explain why readOnlyHint=false is set for what reads like a pure query, leaving that annotation unexplained.

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?

Front-loaded with the access constraint and purpose, then the parameter note, then the sibling caveat — dense but each clause carries information (role requirement, no-phone-number rule, send-boundary warning). Slightly cluttered with bracketed platform notation but no filler sentences.

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 output schema and 5 undocumented parameters, the description covers purpose, access, and the SMS-send boundary but never sketches the return shape (candidate list vs. per-guest progress) or resolves the parameter semantics. Adequate as a minimum-viable definition, but an agent lacks enough to call it precisely.

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 0% across 5 parameters, and the description only says 'q/scope/cursor/selectedIds 同App' — it names the parameters but gives no semantics, no mention of the scope enum values (organization/public), and never mentions the required activityRef. With zero schema-level documentation, the description fails to compensate.

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 and resource: query cloud-guest candidates, authorization status, and real SMS progress, plus the negative constraint '无手机号' (no phone numbers). It differentiates itself from the sibling draft tool. Slight deduction because platform-specific jargon ('云嘉宾') is not unpacked, but an agent can still tell what it retrieves.

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?

Explicitly states the access prerequisite (【需要登录·主办方】 = login + organizer role) and names the alternative route: draft_activity_guest_sms only drafts, whereas actual system SMS must be sent by the person in the App and confirmed. That is clear when-to-use guidance with a named sibling, though there is no explicit 'when not to use' for other status tools.

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