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

Annotations only cover readOnly/openWorld; the description adds the non-obvious behavioral fact that unauthenticated calls are silently truncated to 24 hours while a free key unlocks the full 7 days, which directly affects result interpretation. It does not discuss pagination or whether the ranking is recomputed live, so not a 5.

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 ranking definition and window are front-loaded in a single tight clause, then the access caveat. The URL plug is slightly promotional but still carries actionable information.

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 structure needn't be explained; what matters — ranking basis, time window, and the auth-dependent data truncation — is all present. Only the interaction between limit and the truncation behavior is left unstated.

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?

Only one parameter and schema description coverage is 100% (limit with default and max already documented in the schema). The description adds no semantics for it, so baseline 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?

States a specific verb (ranked), resource (Hyperliquid vaults), ranking metric (net deposits = deposits minus withdrawals) and window (last 7 days), plus an included field (depositor counts). This cleanly separates it from siblings like get_vault_operations (per-vault ops) and get_pnl_leaderboard (PnL-ranked).

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?

Implicitly tells the agent this is the leaderboard/ranking entry point rather than a detail lookup, but never names an alternative sibling or states when not to use it. No preconditions beyond the key note are spelled out.

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