options_chain

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

Annotations already indicate readOnlyHint=true and destructiveHint=false. The description adds valuable behavioral context: returns both calls and puts, calculates Greeks, defaults to nearest expiration, and limits strikes to save tokens. No contradictions.

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 consists of two efficient sentences. The first states the core purpose, the second provides usage and defaults. No wasted words; key information is front-loaded.

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 7 parameters and no output schema, the description covers defaults, token-saving behavior, and customization options. It could mention return format or rate limits, but for a read-only data tool, it is sufficiently 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 100%, so baseline is 3. The description adds meaning by explaining defaults (omitted expiration uses nearest) and the purpose of all_strikes, strike_min/max for custom ranges. This enhances understanding beyond 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 explicitly states 'Get the full option chain (calls and puts) with calculated Greeks', clearly indicating the verb (Get), resource (option chain), and distinct outputs (Greeks). It differentiates from siblings like options_expirations and options_implied_move.

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 advises using options_expirations first to find valid dates, explains default behavior (nearest expiration, strikes ±20% of price), and provides override options (strike_min/strike_max, all_strikes=true). This gives clear when-to-use and how-to-customize guidance.

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