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

Annotations already declare readOnlyHint and openWorldHint, so the bar is lower. The description usefully adds that the data is anonymous/public and requires no account, which is real context an agent needs before calling.

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 tight sentences with no filler, and the resource and scope are front-loaded before the usage note.

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?

An output schema exists, so return values need no explanation, and annotations cover the safety profile. For a one-optional-parameter read tool the description is nearly sufficient, losing a point only because 'no-argument' glosses over the shelf parameter.

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 sort_id enum values are fully documented in the schema, so the baseline is 3. The description's 'no-argument snapshot' phrasing actually understates the presence of the sort_id shelf selector and adds no meaning beyond the schema.

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: 'List ... Roblox game-ranking shelves ... ranked game cards and their current metrics.' An agent can distinguish it from roblox_search (query-driven) and roblox_game (single game), though it never names those siblings explicitly.

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?

'Use this no-argument snapshot to discover popular games' gives an implied use case, but there is no statement of when to prefer it over roblox_search or what the ranking variants (sort_id shelves) are for. No exclusions or alternatives are offered.

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