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

Goes well past the readOnly/idempotent annotations by disclosing the paid cost ($0.002), the x402 payment-requirements handshake, the no-charge-on-error guarantee, and the concrete shape of the returned ticker data. These are exactly the traits an agent needs before committing to a paid call.

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?

Front-loads the most decision-relevant fact (paid, price) then the resource, then error semantics, then a sample link — no filler. The field enumeration is dense but each item is informative; only the payment-requirements sentence is slightly buried at the end.

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?

No output schema exists, yet the description fully covers the return payload fields, the error case, and the payment response, so an agent can call this correctly and know what to expect. Nothing material is missing for a one-parameter read tool.

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 schema already documents symbol as a base ticker with examples and a pattern. The description adds only the pairing convention ('<SYMBOL>-USDT'), confirming the parameter is the base asset without quote suffix, which is a marginal gain over 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?

States a specific verb and resource: 'OKX spot ticker for any live <SYMBOL>-USDT pair', and enumerates the returned fields (last, bid/ask, spread bps, 24h OHLC, volume). It is distinguishable from get_candles/get_perps by being a single-pair snapshot, but it never names the closest sibling (get_price), leaving that boundary for the agent to infer.

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 implied rather than prescribed: 'any live ... pair' plus 'Unknown pairs return an error and no charge' tells the agent what is and isn't valid input, and the free sample URL offers a safe preview. There is no explicit when-to-use versus get_price or get_candles, nor any statement of prerequisites for the x402 payment flow.

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