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

Annotations already cover the read-only, idempotent, non-destructive safety profile, so the description is free to add value elsewhere and does: it discloses the four possible status values, what is returned on success, and that failures surface the error. It stops short of describing polling cadence or whether status transitions are eventual.

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?

Front-loaded with the purpose in the first clause, then the return shape. Tight and waste-free, though the parenthetical aside about matching 'leaderboard rows' assumes knowledge of another tool's shape.

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 not be enumerated, yet the description summarizes them anyway, which is a bonus rather than a gap. Combined with the one-parameter schema and full annotation coverage, an agent has what it needs to invoke this correctly.

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%, so the single parameter and its provenance are already documented in the schema. The description's only addition is the ownership constraint ('one of your'), which is minor; baseline 3 applies when the schema carries the parameter load.

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 clear verb and resource ('Fetch one of your leaderboard submissions') and adds an ownership scope ('owner-only'), which separates it from leaderboard.mine (list) and leaderboard.submit (write). It does not name those siblings explicitly, so an agent must infer the distinction from the namespace.

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 usage ('one of your submissions', owner-only) but never states when to call this versus leaderboard.mine to enumerate submissions first. The only routing cue, that submission_id comes from leaderboard.submit, lives in the schema rather than the description.

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