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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds genuinely new behavioral context beyond the structured fields: the data source (Deribit public data) and the cost ('$0.002/call'), the latter being useful for call budgeting. It does not mention rate limits or snapshot staleness.

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?

One dense sentence front-loads the resource and return shape, then appends usage and cost. The field enumeration is long but earns its place as a stand-in output schema; nothing reads as filler.

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?

With no output schema, the description must carry the return shape and largely does, spelling out term_structure subfields, put_call and dvol. It leaves top_open_interest[] internals and the semantics of a few fields (e.g. bf25) only lightly implied, a minor gap for a one-parameter 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 0%, but the single parameter is an enum (BTC/ETH) whose values are self-documenting and echoed by the description's 'BTC or ETH'. The description adds no format or constraint beyond what the enum already conveys, so this is baseline-adequate rather than enriched.

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 verb-like purpose (options summary for BTC/ETH from Deribit public data) and enumerates exactly which metrics are returned. It distinguishes itself from the closest sibling (derivs_for) with explicit routing, so an agent can separate it without opening the schema.

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?

'Use for BTC/ETH options implied vol, skew, put/call and max pain; for perp funding use derivs_for' gives clear context plus a named alternative. It stops short of explaining when to prefer options_maxpain over this tool, even though max_pain is listed as a use case here, leaving slight overlap unresolved.

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