get_options_expirations

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

No annotations exist, so the description bears the full transparency burden. It discloses asset eligibility (stocks/ETFs, not mutual funds) and its role in checking options coverage, but doesn't detail return structure or error behavior. Still, for a simple retrieval tool the description adds meaningful context.

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, front-loaded with the primary action. The second sentence lists concrete use cases without fluff. Every sentence 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?

For a one-parameter tool with no output schema, the description covers purpose, supported assets, and usage order. It is complete enough for an agent to invoke correctly, though it could optionally mention the result format for empty/no-coverage cases.

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 100% for the single 'symbol' parameter, so the schema already documents it. The description adds the context of 'single underlying symbol' and asset eligibility, but doesn't introduce syntax or format details beyond the schema, aligning with the baseline of 3.

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?

Description opens with a specific verb+resource: 'Returns the list of available option expiration dates for a single underlying symbol.' It clearly states the tool's scope (stocks/ETFs) and differentiates itself from siblings by positioning itself as the first step before get_options_chain.

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?

Provides explicit usage context: 'Use as the first step before calling get_options_chain to discover valid expiration dates, build expiration dropdowns, or check whether a symbol has options coverage.' It also states an exclusion ('mutual funds are not supported'), giving clear when-to-use guidance.

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