get_volatility_cone

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

With no annotations, the description alone must convey behavioral traits. It explains that the tool computes a comparison of current implied volatility to the historical distribution of realized volatility, and states the return format ('volatility cone data with percentile rankings'). However, it does not disclose read-only status, data source, latency, or error behavior. While the description adds useful context, it leaves out several behavioral aspects that could affect agent decisions.

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 well-structured: a clear first sentence, a brief explanatory paragraph, a bulleted usage list, and an Args/Returns section. Each part adds value, though the conceptual explanation could be slightly more concise. Overall, it is appropriately sized and front-loaded with the core purpose.

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 absence of an output schema, the description adequately covers return values ('volatility cone data with percentile rankings'). It also explains the two parameters and provides use-case context. While it does not discuss limitations, alternatives, or edge cases, the tool is relatively simple, and the description is sufficiently complete for an agent to select and invoke it correctly.

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?

The schema provides only parameter names and types (ticker string, periods string/null) with no descriptions. The description's Args section fully compensates: it defines ticker as 'Stock symbol' and periods as 'Comma-separated periods in days (default "10,20,30,60,90")'. This adds crucial meaning beyond the schema, covering both parameters with format and defaults.

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 the tool's core function: 'Get volatility cone comparing current IV to historical realized volatility.' It names the specific resource (volatility cone) and verb (get), and distinguishes it from sibling tools like get_iv_rank (which compares IV to historical percentile) by focusing on the distribution across time horizons. The additional context about identifying over/underpriced options further refines the purpose.

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 provides explicit 'Use this tool when the user asks about' conditions, listing four specific scenarios: IV vs realized volatility comparison, volatility cone analysis, historical volatility distribution, and whether options are fairly priced. This gives clear when-to-use guidance, though it does not explicitly mention when-not-to-use or name alternative tools (e.g., get_iv_rank), which would elevate it to a 5.

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