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

Annotations already declare idempotentHint and openWorldHint. The description adds useful return-content context (room state, sealed principal card, next steps) and warns the link is secret, but says nothing about occupancy conflicts, token expiry, or failure modes for a network-facing join.

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?

Two short sentences, front-loaded with the action and followed by the return contents. No filler, though 'what to do next' is a slightly vague phrase that could be tighter.

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, the description carries the return-value burden and does so briefly but adequately (room state, sealed card, next steps). For a 2-parameter, fully-documented schema it covers the essentials, lacking only edge-case behavior.

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 both parameters are fully documented in the schema, including the seat-link format and the agent_name labeling example. The description's mention of 'private link' only restates the schema, so the baseline 3 applies.

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 names a specific action and mechanism: taking the principal's seat via their private link, and it clarifies this is a proxied join rather than a plain read. It is distinguishable from get_room and create_room, though it doesn't explicitly contrast itself with get_room.

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 implies you must possess the principal's private link, but gives no when-to-use guidance relative to siblings like get_room, create_room, or wait_for_turn, and no exclusions or prerequisites (e.g., what happens if the seat is already occupied).

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