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

Annotations already declare destructiveHint=true, so the description's burden is to add context beyond that. It does so by specifying that 'status does not renew', 'join preserves its waiting ticket', and 'leave frees the slot without deleting or moving the character'. It also states 'Queued results never defer or replay a gameplay action', providing extra side-effect details. No contradiction with 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?

The description is three sentences, each conveying essential information. The first sentence front-loads the purpose, followed by specific behavioral notes. There is no filler or redundancy, making it efficient and easy to parse.

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 simple tool with two parameters and an enum, the description covers all necessary aspects: the operations, their side effects, and the nature of the character identifier. It does not describe the return format, but given the lack of an output schema and the tool's simplicity, this is acceptable. The description is sufficient for an agent to call the tool correctly.

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?

The schema provides the operation enum and the expectedCharacter pattern, but the description adds meaning to the operation parameter by explaining what each enum value does (status, join, leave). The expectedCharacter description in the schema already clarifies it's a public UUID, not a credential. With schema coverage at 50%, the description compensates well by defining the operation semantics.

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 clearly states the tool's purpose: to explicitly join, inspect, or leave a character's admission. It also clarifies the semantics of each operation, distinguishing it from the sibling tools which deal with acting, memories, observation, etc. The specificity of 'Explicitly' and the explanation of 'status does not renew' and 'join preserves its waiting ticket' makes the tool's function unambiguous.

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?

The description implicitly guides usage by explaining what each operation does: status for inspection, join to preserve a ticket, leave to free a slot. It does not explicitly name alternatives or state when not to use, but the operations are self-explanatory and distinct from the sibling tools. The lack of explicit exclusion is a minor gap, hence a 4.

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