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

Annotations already declare readOnlyHint and non-destructive behavior, and the description adds a meaningful behavioral guarantee: no key is ever requested, the private key never leaves the user, and key-entry prompts are hostile. This goes beyond the schema and annotations by warning about a serious security trap, though it does not describe return formats or ordering.

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 first sentence is excellent: short and front-loaded with the tool's purpose. The second sentence is a long, tangential security notice that, while valuable, is verbose and not specific to leaderboard behavior, so not every word earns its place.

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?

Given the simple optional-filter signature, readOnly annotations, and complete schema, the description provides enough for an agent to invoke the tool correctly. The only real gap is the absence of explicit usage guidance, but the filtered-resource phrase makes the tool's role clear.

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%, so the four optional parameters are already documented. The description only restates the same filter names without adding format, combination, or enum semantics, so the baseline score of 3 is appropriate because the schema carries the parameter-documentation burden.

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 phrase 'Leaderboards by game, variant, division, season' clearly identifies the resource and the available filtering dimensions, distinguishing it from sibling tools like game or my_games. It lacks an explicit verb such as 'list' or 'get,' but the noun-phrase description is unambiguous in context.

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 implies the tool is for viewing leaderboards filtered by the supplied dimensions, but it never explicitly states when to choose it over alternatives or when not to use it. There is no competing leaderboard sibling, so the omission is not severe, but the guidance remains only implied.

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