option_chain

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

With no annotations, the description must carry the burden. It discloses that it provides a chain around the money with a maximum of 25 strikes per side, which is useful. However, it doesn't mention data availability caveats (e.g., some fields may be missing) or the return format, which could be important for the agent.

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 compact, front-loading the core purpose, and uses a helpful backtick notation for code-level terms. Every sentence adds value; no fluff.

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?

The description is quite complete for a tool with 3 parameters, no output schema, and no annotations. It covers scope, parameter semantics, and provides a pointer to option_expirations. Minor gap: it doesn't specify the response's exact structure, but given the lack of output schema, this is acceptable.

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 coverage is 0%, so the description must compensate. It explains the 'strikes' parameter as the number of strikes each side of spot, with a max of 25, and implies 'symbol' and 'expiry' are standard. This adds significant meaning beyond the bare schema, making a 4 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 clearly states it returns an option chain for one underlying and one expiry, with details on strikes, calls/puts, and specific fields like bid, ask, last, implied volatility. It differentiates from sibling tools like option_expirations by focusing on the chain itself, and from options_flow by being a snapshot of the chain at a single expiry.

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 explains the scope (one expiry, around the money) and tells the agent to get expiry from option_expirations, which is a clear contextual cue. However, it doesn't explicitly state when not to use this tool or mention alternatives like options_flow for flow data.

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