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

With no annotations provided, the description carries the burden of behavioral disclosure. It states the tool returns a catalog and instructions, which is a read-like behavior, but it does not disclose whether this is a read-only operation, whether it initializes any state, or what the output format looks like. The description is adequate but not rich.

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 a single, concise sentence that front-loads the welcome context and clearly states the two things the tool does. Every word earns its place, and there is no redundancy or 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?

For a zero-parameter onboarding tool with an output schema present, the description is largely complete. It tells the agent what the tool returns and its purpose. It could be slightly more explicit about whether it is safe to call at any time or if it is only for first-time users, but the output schema likely covers return details.

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 has zero parameters, so there is no parameter semantics burden on the description. The schema is empty and coverage is 100%, meaning there is nothing for the description to clarify. A baseline of 4 is appropriate for a no-parameter tool.

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: it returns the game catalog and explains how to start playing. The verb 'returns' and the resource 'game catalog' are specific, and the onboarding context distinguishes it from the many arcade_* siblings that perform actions, reads, or state management.

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 implies this is the entry point for new users ('Welcome to Token Arcade', 'how to start playing'), which gives some usage context. However, it does not explicitly state when to use this tool versus alternatives like arcade_status or arcade_context, nor does it mention any exclusions.

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