Get OHLC candlestick data

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

The description adds meaningful behavioral context beyond the annotations (readOnlyHint=true, destructiveHint=false) by explaining CoinGecko's candle width selection logic and noting that the chosen width is reported in the result. This is valuable non-obvious behavior that helps the agent interpret the response.

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 two sentences, front-loaded with the core purpose, followed by the necessary candle width behavior. There is no wasted text or redundancy.

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?

Given the tool's complexity (three parameters, one required) and the presence of annotations and an output schema, the description is sufficiently complete. It covers the core purpose and the critical candle width nuance, while the schema handles parameter details and the output schema handles return format.

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% for all three parameters, so the description does not need to elaborate on parameter semantics. The tool description adds context about how 'days' relates to candle width, but this is behavioral rather than parameter-specific meaning. Baseline 3 is appropriate.

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 'Get open/high/low/close candles for a coin', using a specific verb and resource. It distinguishes itself from sibling tools like get_coin_price (single price) and get_market_chart (market chart data) by focusing specifically on OHLC candlestick data.

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 implies usage for obtaining OHLC candlestick data, but does not explicitly state when to use this tool versus alternatives. There is no mention of exclusions or alternative tools, so the usage guidance is only implied rather than explicit.

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