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

No annotations are provided, so the description must disclose behavioral traits. It states 'Daily OHLCV candles' which implies read-only historical data without side effects. However, it does not clarify whether the data is live-delayed, if it requires authentication, or if there are any rate limits. Based on the context, a conservative 3 is appropriate as it covers the basic behavior but lacks depth.

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 a single line without filler, earning its place. However, it could be slightly more structured (e.g., specifying that it returns data for the last N days). It is front-loaded and concise but leaves some gaps that require expansion.

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 has no output schema, a more complete description could explain the return format (e.g., array of OHLCV objects). It only describes input behavior. With no annotations, it is minimally adequate for a simple 2-parameter tool but lacks details that would help an agent interpret results or handle errors.

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 0%, so the description must compensate for the two parameters but does not. It mentions 'daily' but doesn't connect to the 'days' parameter (e.g., how many days back). 'Symbol' is self-explanatory from the schema but the description adds no additional context. Since there are only 2 parameters and no compensated semantics, a baseline 3 is fair.

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 uses specific verbs ('OHLCV' implying open, high, low, close, volume) and a resource ('candles' for a venue symbol). It clearly states it provides daily data. However, it does not differentiate from sibling tools like 'history' which could also involve time-series data, so a 5 is not warranted.

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 retrieving OHLCV candle data for a symbol. However, it provides no guidance on when to use this tool versus alternatives like 'history' or 'calendar', nor does it specify any prerequisites or exclusions (e.g., date range limitations, symbol format). Only implied context from the sibling names is available.

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