get_historical_volatility

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

Annotations are absent, so the description carries the full burden. It discloses that the tool returns a time series of historical volatility data points, but it does not mention granularity, time range, or the exact structure of the returned data. The behavior is understandable but only partially transparent.

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 clear sentence with no filler. Every word contributes to identifying what the tool returns and for what kind of asset.

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?

For a one-parameter read-style tool, the description is enough to select and invoke it. However, with no output schema and no annotations, it leaves unclear the exact data-point format, available historical range, and volatility calculation details. Some additional specificity would round it out.

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 100%: the only parameter, currency, is fully described with an enum of supported values. The description adds no additional parameter meaning beyond what the schema already provides, so the baseline score of 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 states a specific verb and resource: 'Get historical volatility data points for a currency index over time.' The word 'historical' and 'over time' help distinguish it from the sibling get_volatility_index, though it does not name the alternative explicitly.

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?

There is no explicit guidance about when to use this tool versus alternatives such as get_volatility_index or get_tradingview_chart_data. The phrasing implies a historical use case, but the description leaves the agent to infer routing from sibling names rather than stating exclusions or conditions.

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