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

Annotations already mark this as read-only, idempotent, and non-destructive, so the description doesn't need to repeat safety cues. It adds valuable behavioral context beyond the annotations: data comes from OKX, the response labels the venue, and symbol variants resolve to the same contract. This meaningfully informs an agent about cross-venue 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 compact and front-loaded with the core purpose, then covers symbol flexibility and venue behavior in two additional sentences. Every sentence earns its place without redundant phrasing or 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?

For a read-only data snapshot with no output schema, the description adequately covers what the tool returns, how symbols are interpreted, and the venue caveat. The schema covers remaining parameter details, so an agent has what it needs 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 covers 100% of parameters with detailed descriptions, including defaults, allowed values, and symbol normalization examples. The tool description adds no parameter-specific semantics beyond the schema, so the baseline of 3 is appropriate.

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 action—taking a 'snapshot in one call'—and lists the exact metrics included (funding rate, open interest, taker buy/sell volume/CVD, long/short ratio). It also differentiates this combined tool from the individual metric sibling tools by emphasizing that all data comes in a single call.

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 makes the use case clear: when an agent needs multiple perp metrics at once, this tool is the one-call option. It also provides important venue guidance by explaining that OKX is the data source and that non-OKX symbols are resolved to OKX contracts, which helps avoid incorrect assumptions about venue.

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