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

Annotations already establish readOnly/destructive/openWorld, so the description's job is otherwise; it delivers real additional context: per-call cost of US$0.002, a 3-free-calls-per-day quota, and the 'arithmetic, not advice' disclaimer that sets expectations about output. It lacks any note on precision, rounding, or what happens at extreme leverage, but the cost and quota disclosure is genuinely useful to an agent budgeting calls.

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?

A single front-loaded sentence that opens with what is computed and closes with cost and quota; the parenthetical contract qualifiers are dense but necessary. Slightly list-like in the middle, but nothing is wasted.

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 values need not be explained, the input schema fully covers all five parameters, and the description supplies the missing commercial context (price, free tier) plus the contract-type constraint. Nothing an agent needs to invoke it correctly is absent.

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%, so the baseline is 3 and the schema already documents side, entry, leverage, size_usd default, and the funding_hourly example format. The description only adds that the funding rate you supply is used to derive a daily funding cost, which clarifies intent but not parameter syntax beyond the schema.

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?

Names a specific computation (liquidation price) scoped to a precise instrument class (leveraged perpetual futures, isolated margin, linear contracts), and enumerates outputs: liquidation price, distance to it, margin, notional, and daily funding cost. An agent can immediately distinguish this from generic price tools like crypto_prices.

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 instrument scope (isolated margin, linear contracts) implicitly tells the agent when the result is valid, and the pricing line gives a cost consideration for calling it. But there is no explicit when-to-use/when-not guidance and no named alternative among the 40+ siblings that cover market data.

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