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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds that no credentials are needed, which is useful behavioral context, and it indicates the returned origin information. It does not cover rate limits, ordering, or other return details, so it adds moderate value beyond 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 a single concise sentence with no wasted words. However, the phrase 'with the origin games are served from' is grammatically awkward and slightly reduces clarity, preventing a perfect score.

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, read-only list tool with annotations covering safety, the description is largely complete: it states what is returned and that credentials are not required. It could mention ordering or return structure, but with no output schema and a simple contract, this is a minor gap.

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 schema coverage is 100% and there is no parameter semantics to explain. A baseline of 4 is appropriate because the description does not need to compensate for any parameter documentation gaps.

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 that it lists every approved experience currently playable on arcade.fun, including the origin games are served from. The verb 'list' is implied by the title and the read-only nature, and it is easily distinguishable from mutation-oriented siblings like create_experience or upload_build. However, it does not explicitly name sibling tools, so it stops short of a 5.

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 provides no explicit guidance on when to use this tool versus alternatives such as experience_status. It only notes 'Needs no credentials,' which is a behavioral detail rather than a usage condition. There is no when-not-to-use or alternative routing.

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