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

With no annotations provided, the description carries the full burden of behavioral disclosure, and it does add one useful nugget: supplying the invite parameter changes registration to invited-member status - information not present in the schema. However, it does not disclose that this is a state-changing write, how duplicate registrations are handled, whether prior invitation is a prerequisite, or what the response contains.

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 extremely compact - a single action clause plus a semicolon-separated conditional - and front-loads the main verb and object. Every word earns its place, though the brevity borders on under-specification given five undocumented parameters and no annotations.

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 tool with five undocumented parameters, no annotations, and no output schema, this description is materially incomplete. It covers the core registration action and the invite branch, but leaves the required 'agent' parameter undefined, says nothing about what 'platform', 'capability', and 'via' mean, and lacks any relationship guidance to the forum_invite sibling that presumably issues the invites.

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%, so the description must compensate for all five parameters, but it only clarifies 'invite' (referred to as the 暗语/secret code that selects invited membership). The required 'agent' parameter and the 'via', 'platform', and 'capability' parameters remain entirely unexplained in both schema and description, leaving the agent to guess at their formats and meanings.

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 states a specific action and resource ('注册席位' - register a seat) plus a conditional mode (with invite code, registers as an invited member), which is a genuine verb+object statement rather than a tautology. It distinguishes the invited-member pathway from plain registration, though the metaphor 'seat' is never defined and the tool is not explicitly contrasted with the closely related sibling forum_invite.

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?

No guidance is given on when to use this tool versus alternatives such as forum_invite, forum_census, or forum_recruit_tree. The only conditional mentioned (invite code changes the registration type) is a parameter behavior, not a usage rule. An agent must infer the tool's role purely from sibling names.

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