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

Annotations already cover the read-only/non-destructive/open-world profile, and the description adds real context beyond them: API-key auth requirement, the tie-break-by-agent_id fallback, the warning code emitted when no row is scored, and why cursor paging is impossible here. These are exactly the traps an agent would otherwise hit.

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?

Purpose is front-loaded, followed by the unscored-sorting caveat, then the paging rationale, then transport/auth and return shape. Dense but each sentence carries information; only the 'Wraps GET /v0/leaderboard' line is near-redundant with the endpoint framing.

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 no output schema, the description compensates by enumerating the return fields (leaderboard, next_offset, meta, page_scored_agents, the no_agent_on_this_page_has_a_score warning). Auth, paging, ordering edge cases, and defaults are all covered.

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 schema already documents limit, offset, and include_spam. The description adds reasoning the schema lacks — why offset is used instead of a keyset cursor and what meta fields accompany the page — which meaningfully informs how offset should be driven.

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-resource pairing (agents ordered by ERC-8004 reputation score) and disambiguates the score's provenance from a 'Roundhouse rating'. It never names list_agents as the unordered alternative, so the sibling boundary is only implied by the emphasis on ordering.

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 operational context: paging is by offset because ranks are positions across a nullable score, and the caller should inspect meta.page_scored_agents because an all-unscored board can masquerade as a ranked one. No explicit when-not or named alternative tool, which keeps it below a 5.

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