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

Annotations only supply destructiveHint=false, so the description carries the burden and does so well: login requirement, that the invitee is notified, on-platform-only restriction, return payload excludes phone numbers and forwardable tokens, reuse of still-valid pending invites, and no persistent dedup under concurrency. These are exactly the behavioral traits an agent cannot get from schema or annotations.

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-loads the login gate and purpose, then stacks preconditions and edge-case handling; nearly every clause is load-bearing. Minor redundancy between '并发无持久去重保证' and '服务没有持久请求去重键,' which restate the same caveat.

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?

Covers auth, side effects, invite-type limits, return-payload exclusions, idempotency behavior, and retry policy — strong for a mutation tool with no output schema. The only substantive gap is that the four input parameters remain undefined in both schema and description.

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 4 parameters, so the description must compensate — but it only obliquely references the goal initiator, the invitee, and '内容'. The message and contribution fields (with their 500/60 char limits and intended content) are never explained, leaving real ambiguity at invocation time.

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 — the goal initiator sends a collaboration invitation to a designated on-platform user — and scopes it with '仅支持站内定向邀请,' which separates it from SMS/guest-link invite siblings. It does not name an explicit alternative tool, so differentiation is inferred rather than stated.

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 the prerequisite (existing authorization for both invitee and content) and, more usefully, an operational rule: after an unclear result or timeout, query current state rather than auto-resending. No sibling tool is named as an alternative, which keeps it below a 5.

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