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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and openWorldHint=false, so safety is covered. The description adds genuinely useful behavioral context by specifying that basis is annualised and that coverage is limited to exchanges the service covers. It does not describe return ordering, units, or how perp funding is expressed, which leaves gaps.

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?

One dense sentence, front-loaded with the primary output (annualised basis) and the secondary metric (perp funding). Every clause carries information and there is zero filler.

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?

For a simple read-only single-parameter tool this is close to sufficient, but with no output schema the description should say more about the shape of the response — currency/units of the basis, whether perp funding is annualised or raw, and how results are ordered across exchanges. As written the agent knows the concept but not the return layout.

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% and the single 'base' parameter is documented with examples (BTC, ETH, SOL), so the schema carries the load. The description's 'one coin' reinforces the semantic mapping but adds nothing beyond the schema, which is the baseline 3 for a fully documented single parameter.

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 (annualised basis of every delivery future plus perp funding) scoped to one coin across covered exchanges, which an agent can distinguish from siblings such as basis_trades or funding_rates. It doesn't explicitly name a sibling it replaces, but the verb+resource combination is concrete.

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?

There is no statement of when to choose this over basis_trades, boros_futures_basis, pair_breakdown, or funding_rates, and no prerequisites or exclusions are given. The agent must infer the use case from the purpose sentence alone.

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