get_zero_dte

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

With no annotations, the description carries the full burden. It discloses the output contents (gamma exposure, flip level, etc.) and a behavioral limitation (only for daily-expiration tickers on trading days). It implies a read-only operation through 'Get', though it does not explicitly state safety, permission needs, or error 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 well-structured with separated sections for purpose, contents, usage guidance, and args. It is slightly wordy but every sentence contributes to understanding. The bullet lists improve readability without being excessive.

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 single-parameter tool with no annotations and no output schema, the description covers the tool's purpose, when to use it, its limitations, and the parameter. The return description ('0DTE analytics payload') is vague but acceptable given the detailed list of included metrics. It is sufficiently complete for an agent to select and invoke the tool correctly.

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 only declares 'ticker' as a required string with no description. The description adds essential meaning: 'ticker: Stock symbol with 0DTE listings (e.g., "SPY")'. This clarifies the expected value and its relevance to the tool, compensating fully for the schema's lack of detail.

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 opens with a specific verb+resource: 'Get 0DTE (same-day expiration) analytics for a ticker.' It differentiates from siblings by emphasizing same-day expiration and lists distinct components (gamma exposure, flip level, max pain, theta decay, chain) that are unique to this tool compared to get_gex, get_max_pain, get_options_chain, etc.

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 explicitly states when to use the tool with bullet points ('0DTE setups or same-day options', 'Intraday gamma/pinning levels', 'Today's expiration chain') and provides a constraint ('Only meaningful for tickers with daily expirations... on trading days'). It does not name alternative tools for when not to use it, but the context is clear.

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