get_expirations

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

With no annotations, the description carries the burden of behavioral disclosure. It discloses the operation (listing), chronological sorting, and the USDC/underlying nuance. However, it does not mention what the response looks like, whether the operation is read-only, or any potential errors if underlying is omitted for USDC.

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 sentences with no filler: the primary purpose and the key edge case are stated directly. The most important information is front-loaded, and every clause earns its place.

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 covers the core purpose and the one non-obvious usage (USDC + underlying). With no output schema, it leaves the exact return shape slightly underspecified, but 'list of expiration dates' is reasonably inferable. The main gap is that it doesn't explain behavior for other currency/underlying combinations, which is a minor omission for a moderate-complexity tool.

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 the schema already documents all three parameters. The description's note about USDC and underlying largely repeats the schema's 'REQUIRED for USDC' message, adding minimal new meaning. This matches the baseline of 3 for full schema coverage.

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 states a specific verb ('List') and resource ('available option expiration dates for a currency'), and adds a sorting detail ('sorted chronologically'). This clearly distinguishes it from sibling tools like get_options_chain or get_instruments, whose purposes are broader or different.

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 contextual guidance for the USDC currency case ('use underlying to filter ETH vs BTC options'), which is exactly the kind of conditional usage an agent needs. It stops short of explicitly naming alternative tools or stating when not to use this tool, but the context is clear enough for most scenarios.

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