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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds real value beyond that: newest-first ordering, the pagination contract ('pass the last play's `at` as `before`'), and that a luck-board play carries a `verify` token to forward to verify_play. It stops short of describing rate limits or response shape in detail.

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?

Four short sentences, front-loaded with what the tool returns, then when to use it, then the two operational tips. Every sentence earns its place with no filler.

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?

There is no output schema, so the description carries the return burden, and it does: it names the fields returned (stake, payout, state, lifetime totals, verify token) and the ordering. Combined with fully documented params and covering annotations, an agent has everything needed to call it 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?

Schema coverage is 100%, so baseline is 3. The description goes further by explaining the intended value of `before` (the previous page's last play `at`), which is a usage pattern the schema field text does not fully convey. `limit` is left 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+resource ('Everything you've played') and enumerates the resource subtypes (luck boards, invented games, skill runs, Arena and room seats). It explicitly contrasts with get_me for balance, letting an agent separate it from a near sibling without opening a schema.

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?

Gives concrete use cases ('review results or find a round to check'), names the alternative for balance ('use get_me'), and routes the verification case to verify_play. Both when-to-use and alternatives are explicit.

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