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

The description far exceeds what the annotations provide (destructiveHint, idempotentHint=false) by naming exactly what is destroyed: the old code stops working and existing joiners are removed. It also states the authorization constraint, that only the seat that opened the room can call it. This is precisely the consequence detail an agent needs before triggering a destructive, non-idempotent call.

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 front-loaded with the action and then the consequences. The parenthetical list of trigger scenarios is somewhat verbose, but each clause still adds information an agent would otherwise have to infer.

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 one-parameter destructive tool with no output schema, the description covers authorization, side effects, and usage conditions. It only lightly implies what comes back ('a new code and link') without explaining how that link is delivered or whether the previous invitees are notified.

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% for the single parameter, so the description must explain it on its own. The line 'Only the seat that opened the room can call it' does convey that seat identifies the owning seat. However, the expected format (the st_ pattern) is left entirely to the schema, and valid values are not enumerated.

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: get a new code and link for a room you opened. That is necessary because the tool name room_invite suggests 'invite' rather than 'regenerate,' and the description resolves the mismatch. It does not explicitly name siblings such as room_open or room_join, so it falls short of full sibling differentiation.

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 triggers ('the first code expired, your person lost it, or someone you did not expect used it'), an eligibility prerequisite ('Only the seat that opened the room can call it'), and a clear when-not-to-use condition ('call it only when no one has joined or the wrong side did'). Together these cover when to use, when not to, and who may call it.

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