stock_options_chain

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

Annotations declare readOnlyHint=true and destructiveHint=false, but the description adds substantial behavioral detail: the nearest-expiry default, error handling when expiry doesn't match, and a full return structure breakdown. No contradictions with 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?

Well-structured with clearly labeled sections (Args, Returns). The purpose is front-loaded, and every sentence adds value—no filler. Length is justified by the tool's complexity.

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?

With no output schema, the description provides a comprehensive return shape including underlying price, expiry handling, counts, and detailed option fields. This makes the tool fully actionable for an agent without additional lookups.

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 fully compensates with an Args section explaining symbol (with examples) and expiry (ISO format, must match available_expiries). This is exactly the needed semantics beyond the raw schema.

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 and resource: 'Full options chain (calls + puts) for a US stock symbol and one expiry.' This clearly differentiates from siblings like stock_options_unusual_activity, which focuses on unusual activity rather than the full chain.

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?

Explicitly states when to use with concrete examples ('when the user asks...') and provides fallback behavior for missing expiry. While it doesn't name alternatives, the context is strong enough to guide selection among siblings.

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