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

Beyond the annotations (readOnly, idempotent, etc.), the description discloses the paid nature ($0.25 via x402), self-containment of the decision_id, and the exact output components. It also cautions to keep the decision_id, adding practical behavioral context.

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, front-loaded with the core value proposition, and each sentence earns its place — output summary, usage guidance, decision_id retention, and cost. No fluff or repetition.

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?

Given the lack of an output schema, the description adequately covers what the tool returns (decision_id, hash, candles), when to use it, and its cost. It also highlights a critical user action (keep the decision_id), making the description self-sufficient for safe invocation.

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 100%, so all parameter meanings are already documented. The description adds no extra parameter-level semantics beyond restating general purpose; it focuses on outputs and usage cost, which is acceptable but not additive to parameter understanding.

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 clearly states it produces a 'Settlement verdict plus a citable record' including a signed decision_id, integrity hash, and candles. It explicitly contrasts with 'just need to know' scenarios, distinguishing it from simpler price lookup tools like get_crypto_spot or resolve_price_event.

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?

Provides explicit when-to-use ('when the answer may later have to be defended') and when-not-to-use ('not when you just need to know'). However, it does not name specific alternative tools, only implies them, so it falls slightly short of full explicitness.

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