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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, and the description adds two genuinely non-redundant traits: the $0.001 USDC per-call cost and the byte-identical contract with the OKX REST endpoint, which lets the agent predict the exact response shape. This is real added context, though it stops short of disclosing failure modes or rate limits.

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?

Three short sentences, each earning its place: the data payload is front-loaded, followed by the cost disclosure and the exact endpoint contract. Zero filler or repetition of what the schema/annotations already state.

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 single-parameter tool with a rich annotation set, a documented parameter schema, and an output schema present, the description is complete: the agent knows what data it receives, what it costs, what endpoint contract to expect, and how to specify instId. Nothing needed for a correct call is missing.

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 instId description is already strong (BASE-QUOTE format with BTC-USDT and ETH-USDT-SWAP examples plus [required]). The tool description adds nothing about the parameter beyond referencing 'one OKX instrument,' so the schema carries the load and the baseline 3 applies.

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 precisely enumerates the data payload (last, bid, ask, 24h open/high/low, both volumes) for 'one OKX instrument,' which unambiguously identifies this as a single-instrument spot ticker fetch. The OKX naming and the ticker-specific fields clearly distinguish it from sibling tools like market_okx_candles, market_okx_depth, and other exchanges' ticker tools.

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 scope is clear: the agent knows it gets one instrument's ticker snapshot, which implies when to call it. However, there are no explicit when-not-to-use statements or named alternatives (e.g., no guidance to use market_okx_candles for history or market_okx_depth for order book data), so routing decisions are left to inference.

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