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

The tool clarifies its fundamental nature: measuring 'how fast a move options price, not its direction.' It provides rich behavioral context by listing specific calculated timeframes and statistical measures like '1y percentile' and '25-delta risk reversal'.

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 dense and technically overloaded, making it hard to read, but it prioritizes information density. Every clause provides a high-value piece of information regarding the tool's content.

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?

While the input scope is meticulously covered, the definition lacks any mention of the output structure or how the return data for different underlyings should be interpreted, which is a gap given the complexity.

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?

Since schema coverage is 100%, the schema handles the technical requirements (string input). The description adds semantic value by demonstrating how the input should be structured (comma-separated list) and used (for comparison).

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 is extremely clear and functions almost as a technical specification, detailing exactly what kind of implied volatility metrics are provided (e.g., DVOL index, IV term structure, skew). It specifically states the data source (Deribit).

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?

It explicitly suggests a primary use case for the input parameter: 'Pass several underlyings ("BTC,ETH") to compare.' While it doesn't explicitly list alternatives, it clearly defines the specific financial context of the tool.

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