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

Annotations already declare it read-only, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds real value beyond that by setting expectations that counts are advisory ('positive online counts when available') and that a result does not guarantee a match — behavior an agent cannot infer from 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?

Two tight sentences with no filler, and the caveat is front-loaded. The wording 'availability context' and 'when available' is vaguer than necessary and costs some precision.

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 an output schema and full annotation coverage, much is already carried elsewhere. However, the description never states what availability is being queried or how 'when available' conditions the response, leaving the central object of the call implicit.

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% and the single 'game' parameter is documented with its source (list_games), so the schema does the work. The description adds nothing about the parameter, which is acceptable at full coverage but not better than baseline.

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 verb is clear (check) but the resource is fuzzy: 'public availability context and positive online counts' never names what is being checked (sessions, queues, teammates). The title supplies 'session' but the description must stand on its own, and it does not distinguish this from find_session.

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 on when to call this versus find_session or create_booking_link, and no prerequisites stated. The clause 'A teammate accepts from the queue' hints at the calling context but doesn't say when an agent should prefer this tool.

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