IV Rank

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

Annotations already provide readOnlyHint=true, and the description adds behavioral detail beyond that: it interprets high/low IV Rank ranges and clarifies the output includes 'interpretation and strategy recommendations.' This gives useful context about what the tool returns and how to interpret it. It doesn't contradict annotations.

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 with an opening summary, brief explanatory paragraphs, a clear usage list, and an Args/Returns section. Each section earns its place and the text is not bloated. The heading/repetition of the description and title is minor, but the overall structure helps scannability.

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 two-parameter, read-only tool with no output schema, the description is nearly sufficient. It explains what is returned ('IV rank data with interpretation and strategy recommendations') and how lookback_days affects the result. It could be more explicit about the exact fields in the response, but given it is a simple read tool with a clear interpretation, the context is reasonably complete.

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%, but the description compensates well with an Args section. It explains ticker with concrete examples ('AAPL', 'SPY') and lookback_days with its default and meaning ('default 252 = 1 year'). This adds practical semantics that the schema lacks.

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 opens with a specific verb+resource: 'Get IV Rank and percentile for a stock,' clearly stating the tool's core function. It also explains the conceptual meaning of IV Rank and provides threshold meanings (high >50, low <30). However, it does not explicitly differentiate this from related sibling tools like get_volatility_risk_premium or find_iv_opportunities.

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 includes a dedicated 'Use this tool when the user asks about...' section with four concrete use cases, such as 'Whether options are expensive or cheap' and 'Premium selling/buying opportunities.' This is clear and actionable, but it lacks explicit 'when not to use' guidance or references to alternative tools, so it falls short of a 5.

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