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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description still adds value beyond them by disclosing an auth constraint ("No API key needed") and by describing what the response contains, with and without the optional game argument.

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?

Two short sentences, zero filler, with the base behavior stated first and the conditional behavior second. Nothing repeats the name or title needlessly.

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 one-optional-parameter read-only tool with full annotation coverage, the description covers purpose, chaining, auth, and return contents. Exact field names in the response are left unspecified, which is a minor gap given there is no output schema.

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% and the enum already enumerates valid game keys, so the schema does most of the work. The description adds meaning the schema does not: the optional game argument is not just a filter but a request to enrich the response with tags intended for search_servers, which explains why an agent would set it.

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?

"Every game VoxelRank lists, with its key and how many public servers it has" names the resource and the exact payload returned (game keys plus public server counts), and the mention of tags "for search_servers" distinguishes it from the sibling that actually queries servers. It stops short of a crisp verb-first statement but the scope is unmistakable.

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 gives a concrete usage cue: pass a game to get tags that feed search_servers, which tells an agent how this tool chains into a sibling. It does not state when to call this versus search_servers or top_servers directly, so there is no explicit exclusion guidance.

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