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

Annotations already declare readOnlyHint and idempotentHint, so the safety profile is covered. The description adds meaningful behavior beyond that: it discloses the exact link fields (canonical_url and UTM-tagged open_url), the source field, and the distinction between item-level and response-level attribution for picks without a game id.

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 core purpose is front-loaded in the first clause, followed by dense, relevant detail about links and source attribution. It is slightly run-on but every clause contributes useful information with no 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 one-parameter, read-only, idempotent tool with an output schema, the description covers purpose, source, link fields, and an attribution edge case. It does not mention ordering or how 'underrated' is determined, but nothing essential is missing for correct usage.

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%; the input schema already fully documents the only parameter, limit, including its default, minimum, and maximum. The description adds no additional parameter-level meaning, so the baseline of 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?

The description uses a specific verb and resource: it returns community-picked underrated co-op games from Co-Op Now's Hidden Gems list. This clearly differentiates it from the more general sibling tools search_games, find_coop_games, and get_game.

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 makes the tool's domain clear: it is for retrieving curated hidden-gem co-op games from a specific source. It also gives a concrete behavioral instruction about including the co-op.now link when the client supports links or citations, though it does not explicitly name sibling alternatives or exclusions.

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