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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds genuinely new behavior: hosted games ranked before community games, the per-game fact bundle returned, and the important rule that community results are dropped when filtering by multiplayer, age or size. No contradiction with 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?

Three sentences, front-loaded with the action, then return contents, then ranking and the empty-result rule. The parenthetical fact list is long but each item is decision-relevant; nothing is redundant.

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 12 optional parameters and no output schema, the description does the necessary work of sketching the return shape (facts, store page, link) and the ranking order. It leaves pagination/limit and how query matching weighs fields to the schema, which is acceptable but not fully complete.

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 description coverage is 100%, including enums, defaults and ranges, so the schema already carries parameter meaning. The description adds only the ordering implication of results and the empty-result case, not syntax or filter interaction beyond what the schema states, so baseline 3 applies.

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 and resource ('find games on Cassette') and what the results contain, so the agent knows exactly what it retrieves. It does not distinguish itself from the sibling similar_games, which could overlap for a vague query, so it falls 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?

Gives clear operating guidance: use a plain-language query or omit it to list most-played games, and treat an empty result as a real answer to relay to the user. It never names an alternative tool (e.g. similar_games) or says when this is the wrong choice, so exclusions are missing.

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