term-structure

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

With no annotations, the description carries the full burden, and it does disclose that the result is a point-in-time snapshot of ATM IV by expiry, which is real behavioral information. However, it says nothing about what happens when an expiry series is missing, what permissions or data availability is required, or how large the response may be.

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?

A single front-loaded sentence with no filler; nothing is wasted. It is efficient, though its brevity is partly the source of the specification gaps noted elsewhere.

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 4-parameter, 3-required tool with no annotations, no output schema, and two undocumented required parameters, one sentence is not enough. The agent gets no sense of the return shape (expiries, IV values, units) or of the required timestamp and symbol semantics.

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 only 50%: `rate` and `asset_class` are well documented in the schema, but `at_ns` (a required timestamp) and `underlying` (required) are bare. The description mentions neither parameter nor explains the timestamp semantics, so it does not compensate for the gap.

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 resource (ATM implied volatility per expiry) and a scope (one underlying, one instant). It is clear what data comes back, but it never names its obvious sibling iv-surface, so the agent must infer that term-structure is the ATM slice rather than the full surface.

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?

There is no explicit guidance on when to pick this over iv-surface, vol-skew, or risk-reversal. The phrase 'at one instant' faintly implies a snapshot rather than a time series, but nothing tells the agent when this tool is the right choice or what prerequisites it has.

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