volatility

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

With no annotations, the description carries the full behavioral burden, yet it discloses nothing about authentication, rate limits, caching, freshness, or response shape. It does say what the payload contains (DVOL 30d forward + latest realized vol), which is genuinely useful context, but the operational traits are absent.

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 core sentence is repeated verbatim after an em dash, consuming space with zero added information. The example is useful and the intent is front-loaded, but the duplication is clear waste in an otherwise short description.

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-optional-parameter read tool with no output schema and no annotations, the description covers the essentials: what data comes back and for which assets. It omits whether the response is a time series or a single reading, the lookback for 'realized' volatility, and any auth or rate-limit context.

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 optional currency parameter is already documented as 'BTC (default) or ETH.' The description's 'for BTC or ETH' merely corroborates the schema rather than adding syntax, defaults, or validation detail, so the baseline of 3 applies.

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 names a specific data source (Deribit) and concrete payload: the DVOL implied-vol index (30d forward) plus latest realized volatility, scoped to BTC or ETH. That is far more specific than a tautology and distinguishes it from siblings like atr or momentum_score, though it never explicitly contrasts itself with those tools.

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 when-to-use or when-not-to-use guidance, and no named alternative among the many sibling market-data tools. The only implicit signal is that this returns volatility data, leaving the agent to infer that it should be chosen over atr, momentum_score, or ohlcv on its own.

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