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

Annotations already cover the read-only, idempotent, non-destructive profile, so the bar is lower. The description still adds real context: it is a latest-snapshot view (not a time series, unlike contract_historic), rows are constrained to OI > 0, and the 'Pro' marker signals a subscription/tier requirement.

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?

Two compact sentences: the first front-loads what the tool returns, the second lists filters. Dense and efficient, though the field enumeration is slightly list-heavy.

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 read-only listing tool with no output schema, the description covers the returned fields, the snapshot semantics and the available filters. Remaining gaps (default limit, 'Pro' meaning, response shape) are minor but not fully closed.

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 67%, and the schema itself documents ticker, date and limit formats. The description names the filterable fields (expiry, call/put, min OI) and confirms the OI>0 constraint, adding marginal value but no format or syntax detail beyond the 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?

States a specific verb and resource (option chain for a ticker) plus the exact returned fields, which lets an agent distinguish it from contract_atm and contract_historic. It does not explicitly name or contrast those siblings, so it stops short of a 5.

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 says what can be filtered (expiry, call/put, minimum OI) but gives no when-to-use guidance or comparison to alternatives such as contract_atm or contract_historic. Usage is implied by the filters rather than stated.

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