iv-surface

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

With no annotations, the description carries the full burden of behavioral disclosure and provides essentially none: nothing about permissions, cost, rate sensitivity, what the 'cross-section' actually contains, or how asset_class changes the answer. It implies a read-only computation but never says so.

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 or repetition. It is efficient, though the term 'cross-section' is left unexpanded, making the brevity partly under-specification rather than pure concision.

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 tool with no annotations, no output schema, and 50% schema coverage, one sentence is not enough. An agent still lacks sibling differentiation, timestamp semantics, symbol format expectations, and any description of the returned surface structure.

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 50%, and the description itself contributes no parameter meaning at all. The schema explains rate convention and why asset_class is required, but at_ns (timestamp units) and underlying (symbol format) are undocumented in both places, so the description fails to 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?

The description names a specific resource — an implied-volatility cross-section for one underlying at one instant — which is enough for an agent to know what the tool produces. It does not distinguish this from close siblings such as vol-skew or term-structure, leaving the agent to infer that this is the full strike-by-expiry surface rather than a skew or a time slice.

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 guidance on when to use this tool versus vol-skew, term-structure, or risk-reversal, all of which sit in the same options family. The only usage-relevant detail ('one underlying at one instant') describes scope but not selection criteria.

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