get_option_chain

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

With no annotations, the description carries the full behavioral burden. It discloses the return format (including expiry format DD-Mon-YYYY and default to nearest expiry), and lists the specific data returned. It implies a read-only operation without stating it, and does not mention error handling or edge cases, but the provided details are sufficient for a data-retrieval tool.

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 concise, composed of three sentences, and front-loaded with the core purpose. It efficiently lists return items without fluff, and places the expiry format note at the end. Every sentence adds value, making it well-structured and easy to parse.

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?

Despite lacking an output schema, the description enumerates the returned data in detail (spot, expiry list, PCR, max pain, top OI strikes, and a table with specific fields). It covers the expiry parameter and valid symbols, but omits an explanation of 'strikes_around', which is a key parameter. The overall coverage is strong but not exhaustive, warranting a 4.

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?

The input schema has no descriptions (0% coverage), so the description must compensate. It explains the expiry parameter's format and default, and enumerates valid symbols (NIFTY, BANKNIFTY, FINNIFTY, MIDCPNIFTY) for the symbol parameter. However, it does not explain the 'strikes_around' parameter, leaving its purpose and effect ambiguous. Thus, only partial parameter semantics are provided.

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 the tool's purpose: retrieving an option chain from NSE for indices or F&O stocks. It specifies the resource (NSE option chain) and enumerates the returned data (spot, expiry list, PCR, max pain, top OI strikes, and a compact table with fields). It is immediately distinguishable from sibling tools, none of which relate to options.

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 provides clear context on when to use it (for NSE indices or F&O stocks) and specifies the expiry format and default behavior. However, it does not explicitly contrast it with alternative tools or state conditions when not to use it. The absence of explicit alternatives is minor given the uniqueness of the tool, but it prevents a 5.

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