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

Beyond readOnlyHint/openWorldHint, it discloses a concrete rate limit (60 calls per hour), that no candles or signals are returned, the acceptable quote substitutions (USDT/USD/USDC), and the underlying data sources. That is substantial operational context the annotations do not carry.

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 ('Free: before paying') and every clause carries information, but the single long sentence with nested parentheticals is dense and would read better split into two.

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 an output schema present, return values need no explanation, and the description still covers sourcing, intervals, rate limits, and the no-signal caveat. Nothing needed to call it correctly 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 single pair parameter is well documented, so the baseline is 3. The description adds behavioral meaning for that parameter: a different dollar quote can substitute for the one requested, which is not evident from the schema alone.

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 verb and resource ('Look up a pair') and enumerates exactly what the response tells you: support status, candle source (Binance.US, Kraken, Gate, MEXC, XRPL DEX), and accepted intervals. It also differentiates itself from the signal/tooling siblings by stating it fetches no candles and returns no signal.

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?

Gives an explicit call condition ('Free: before paying, check whether a crypto pair is supported') and routes the agent elsewhere for a different need ('for the daily trend use ichimoku_trend'). The free-vs-paid distinction makes the when-to-use decision unambiguous.

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