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

Annotations already cover the safety profile (readOnlyHint, openWorldHint), and the description adds meaningful context beyond them: the normalisation basis (8 hours), the annualisation, and the conditional availability of open interest and volume ('when published'). It does not state whether values are live snapshots or cached, which keeps it short of 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?

Two compact sentences with no filler; the returned-data specification is front-loaded and the use-case hint is deferred to the end. Every clause carries information an agent would otherwise have to guess.

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 one required parameter and no output schema, the description compensates well by enumerating what comes back (normalised and annualised rate, open interest, 24h volume). It stops short of describing the response shape — e.g. that results are per-venue — which leaves a small gap for an agent planning downstream use.

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% and the single 'pair' parameter is a fully enumerated base asset with an example, so the schema carries the semantics. The description adds only the implication that the pair is queried across all venues rather than one, which is a modest gain.

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 description names a specific resource (current funding rate of a perpetual) and its scope (each perp DEX), plus the derived metrics returned (8h-normalised, annualised, open interest, 24h volume). This distinguishes it from siblings like delta_neutral_scanner or cost_per_point, though it never names an alternative explicitly.

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 trailing clause 'Useful for delta-neutral funding trades' gives an implied use case, but there is no explicit when-to-use vs when-not guidance and no routing to the closely related delta_neutral, delta_neutral_scanner, or best_venue tools. An agent must infer the selection criteria.

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