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

ReadOnlyHint and openWorldHint already cover the read-only and open-world aspects, and the description adds useful context about not needing an exchange key and the $0.01 per-call cost in USDC on x402. However, the stated interval range '1m to 1d' conflicts with the schema enum that also allows 1w and 1M, which is misleading behavior disclosure.

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 sentences deliver the core action, use case, and cost information with little waste. It loses the top score because the interval parenthetical is inaccurate and the billing sentence switches to Spanish, which slightly hurts readability.

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?

The tool is simple and all parameters are documented in the schema, but there is no output schema and the description never states the shape of the returned candles (e.g., timestamp, OHLCV fields) or their ordering. Cost and keyless access are disclosed, but the return format remains under-specified.

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 applies: symbol, interval, and limite are already well documented with defaults, an example, and an enum. The description's only param-related addition is the interval range, which actually understates the schema enum and does not add useful meaning.

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 that the tool returns recent OHLC candles for a trading pair at a requested interval, and connects it to trend/volatility/charting use cases. It does not explicitly distinguish this from siblings like precio or mercado, though the candle-specific language makes the resource clear.

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?

It gives clear context for when to use the tool: to compute trend or volatility, to draw charts, and to access market data without an exchange API key. It stops short of naming alternatives or saying when not to use it, so it misses the top score.

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