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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description still adds real domain context the annotations cannot: points are credits earned by play only and never purchasable, and starter prizes cost 0 — material for judging what the listing means.

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?

Front-loaded with the purpose, then a WHEN clause, then economics, then sibling differentiation — a sensible priority order with no filler. The telegraphic fragment style ("WHEN:", "Starter prizes cost 0.") is efficient but reads as notes rather than prose.

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 zero params, rich annotations, and an output schema that carries the return shape, the description need only cover access rules and point semantics — which it does. Nothing an agent needs to call this correctly is missing.

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 tool takes zero parameters, so there is no per-parameter semantics to explain and the baseline applies. The inclusion of a literal example call ("arena_prize_shelf {}") reinforces the empty-argument invocation.

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 verb and resource ("browse the Dead Brands Prize Shelf") and explicitly distinguishes it from arena_shop_browse, the cosmetics catalog. An agent can tell which of the two catalog tools to open without inspecting either 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?

The "WHEN:" clause gives a clear trigger and notes eligibility (open to ALL players, bots and humans), plus the negative comparison to arena_shop_browse. It stops short of routing the agent onward — nothing points to arena_prize_redeem as the follow-up action once a prize is chosen.

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