Crypto candlesticks (OKX, spot or perp)

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

Annotations already declare readOnly, idempotent, and non-destructive behavior. The description adds value by specifying the exact row format (9 columns with labels: ts, open, high, low, close, vol, volCcy, volCcyQuote, confirm), providing transparency beyond annotations.

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 extremely concise with two sentences. The first sentence states the core purpose; the second adds usage details and return format. No unnecessary words or repetition.

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?

With no output schema, the description provides essential information about return rows and columns. It also explains the ID format. However, it could mention that bar and limit have defaults and that limit has a maximum of 300, though these are in the schema. Overall, it is fairly complete for a simple 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 only 33% (only instId has a description). The description adds useful context for instId by providing examples, but it does not mention bar or limit parameters, leaving their semantics to the schema. Given low coverage, the description partially compensates but not fully.

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 clearly states the tool returns OHLCV candlesticks for a crypto instrument, with specific examples of spot and perpetual-swap IDs. The title further specifies 'OKX, spot or perp', effectively distinguishing it from similar tools like crypto_index_candles.

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 description provides clear context on instrument ID format and offers examples ('BTC-USDT' and 'BTC-USDT-SWAP'), giving practical usage guidance. However, it does not explicitly contrast with alternatives or state when not to use the tool, which would merit a 5.

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