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

Annotations already declare the write/non-idempotent/open-world profile, so the description doesn't need to restate that. It adds genuinely non-obvious behavior: the return payload (room URL and WebSocket endpoint) and the collision semantics — a custom roomId is not reserved and can be shared with an existing pond, which is a surprising and important trait for an agent choosing an ID.

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?

Three sentences, front-loaded with the core action and return values, then the sibling routing, then the caveat. Nothing is repeated from the schema or annotations and every sentence carries new information.

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?

Tool is simple (3 optional params, output schema present), and the description covers action, returns, alternative routing, and the main gotcha. It could note whether creation requires any authentication/lifecycle consideration (e.g., how a room is later closed via close_pond), but for a create tool with an output schema this is close to complete.

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 baseline is 3; the description adds meaning beyond the schema for roomId by explaining that supplying one does not reserve it and can cause door-sharing with another room. That's a real semantic addition, though label and source are left entirely to the schema.

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 (mint/create) and resource (Pondchat room / pond) with the medium it supports (video/audio/chat). It explicitly contrasts itself with get_room_info, so an agent can distinguish it from the read-only sibling without inspecting schemas.

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?

Declares itself as 'the only way to create a room' and names the alternative (get_room_info) with the exact condition that selects it — retrieving metadata for an existing roomId. Explicit when-to-use and when-to-use-something-else guidance.

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