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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds real behavioral content beyond that: the sign convention for amounts and what the aggregation buckets produce (daily totals vs. raw hourly payments). It doesn't discuss pagination behavior or limits, but with annotations present this is a solid contribution.

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?

Three short sentences, front-loaded with what the tool returns, then the sign convention, then bucket behavior. No filler and nothing that repeats the schema verbatim without adding meaning.

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 an output schema present, return-shape detail is unnecessary, and the description covers the two things an agent most needs that the schema can't express: sign interpretation and bucket granularity. The unexplained third enum value ('raw') and the absence of any steering versus sibling funding tools are the remaining small gaps.

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 baseline is 3. The description goes beyond the schema's terse 'Aggregation bucket; default 1d' by explaining what 1d and 1h actually yield, which materially helps an agent choose a bucket. Minor gap: the enum also offers 'raw', which the description never addresses and which reads as overlapping with the stated '1h = raw hourly payments'.

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 resource and semantics: funding payments paid or received by a Hyperliquid wallet, broken out per market per bucket. The sign convention ('positive means received, negative means paid') makes the output's direction unambiguous. It doesn't explicitly name how it differs from the nearby get_funding_rates / get_funding_stats siblings, which are market-level rather than wallet-level, so a 4 rather than a 5.

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?

Usage is only implied — an agent can infer this is the wallet-scoped funding tool when it has an address and wants payment history. There is no explicit 'use this when…' statement and no routing to get_funding_rates, get_funding_stats, or get_user_ledger for the adjacent cases. The bucket guidance partially compensates by telling the agent how to pick granularity.

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