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

With readOnlyHint=true already conveying the read-only nature, the description adds valuable context: it is a pure math computation requiring no market data, and it lists the expected outputs (all greeks). This goes beyond the annotation, though it does not detail return format or error behavior.

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 two sentences, front-loaded with the core purpose, and every phrase adds value — 'Pure math — no market data needed' is a meaningful differentiator. No wasted words.

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 self-contained calculation tool with 100% schema coverage and a read-only annotation, the description adequately covers purpose and enumerates outputs. It does not mention Black-Scholes assumptions (e.g., European options) or dte conversion, but these are minor gaps given the tool's simplicity.

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 each parameter already has a clear description (e.g., sigma as decimal). The tool description adds no additional parameter-level detail, so the baseline 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 uses a specific verb ('Calculate') and resource ('Black-Scholes option greeks'), enumerates all the greeks computed, and adds 'Pure math — no market data needed' to distinguish it from data-fetching siblings. This clearly differentiates it from tools like get_option_chain or solve_iv.

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 phrase 'Pure math — no market data needed' signals that this tool is for theoretical calculations without dependence on live market data, providing clear context for when to use it. However, it does not explicitly name alternatives or exclusions, so it stops 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.