Margin borrow rates per venue: the cost of leverage, hourly

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

Annotations already declare readOnlyHint and openWorldHint, so the description doesn't need to re-state safety. It adds valuable context beyond annotations: return content (annualised rate, 30-day hourly series, carry table), data source (ByKaranteli), and venue coverage (Binance and OKX today). No contradiction, and it enriches the behavioral profile.

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 description is a single paragraph with three sentences, front-loaded with the trigger conditions. It is efficient, though slightly packed with several trigger examples and detail. No fluff, but could be tightened without loss of 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?

For a zero-parameter, read-only tool with no output schema, the description is complete: it specifies when to call, what data is returned, the time range, and the source. Nothing essential is missing for an agent to select and invoke it correctly.

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?

The tool has zero parameters, so the schema is trivially complete (100% coverage). The baseline for 0 params is 4, and the description doesn't need to explain parameters. It correctly omits parameter details, which is appropriate.

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 lists specific trigger questions (borrow cost, cheapest venue, stablecoin spike, basis trade carry) and names the exact resource (borrow rates per venue and asset). It clearly distinguishes from sibling tools like get_funding_arbitrage (funding arbitrage) and get_leverage_tiers (leverage tiers), which are about different concepts.

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?

Provides explicit 'when to use' conditions with concrete user queries. Does not mention when not to use or alternatives, but the context is clear and the tool is parameterless, so ambiguity is low. Missing exclusions keep it from a 5.

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