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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds valuable context by enumerating the specific content returned (fields, repair rules, size limits, data-rights, retention policy), going beyond the annotations. It does not contradict annotations; the word 'Return' aligns with read-only behavior.

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 a single sentence that front-loads the verb 'Return' and lists five distinct categories. It is concise and waste-free, though the list is slightly dense. It achieves good structure without being overly long.

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 that an output schema exists (though not detailed in the prompt), the description need not explain return values in depth. It provides a clear inventory of what the tool covers, which is sufficient for an agent to decide to call it. The only missing piece is explicit usage guidance, but that is covered under usage guidelines. Overall completeness is strong.

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?

There are zero parameters, so schema coverage is trivially 100%. Per calibration, 0 params gets a baseline of 4. The description correctly avoids discussing parameters since none exist, and the output schema (though not shown) likely describes the returned structure.

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 starts with 'Return' and specifies the exact resource: accepted CSV and JSON option-chain fields, safe repair rules, size limits, data-rights confirmation, and retention policy. This clearly distinguishes it from sibling tools like option_chain_snapshot (likely data retrieval) and option_validate_snapshot (likely validation).

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 states what the tool returns but does not explicitly say when to use it versus alternatives. It implies usage (when you need schema/field definitions), but lacks explicit routing like 'use for metadata, not for data' or exclusions. For a metadata tool this is a minor gap, but the absence of any alternative guidance makes it a 3.

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