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

Annotations already indicate read-only, idempotent, and non-destructive behavior. The description adds that data may be stale, pointing to as_of_day and stale fields, and notes that next-day outcome stats exist only where enough events are available. This is useful context beyond annotations, though it does not fully explain how to interpret 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?

The description is two sentences, front-loaded with the core purpose, followed by a clear caveat about data staleness. Every sentence earns its place with no redundancy.

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 input parameters and an output schema available, the description need not explain return values. It covers the key elements: what the tool reveals, the staleness caveat, and the descriptive-only nature. It could clarify what 'pairs' refers to, but that is domain-specific context rather than a critical gap.

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 tool has zero parameters, so the baseline is 4. The description mentions as_of_day and stale but these are response fields, not inputs. No additional parameter semantics are needed.

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 identifies pairs at record highs/lows or in the top/bottom 5% for funding, open interest, or liquidations relative to their own history, and provides next-day outcome stats. This is a specific, resource-focused purpose that distinguishes it from siblings like market_overview or market_history.

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?

It provides context that the tool covers the latest recorded day, not necessarily today, and instructs to check as_of_day and stale before treating data as current. However, it does not explicitly name alternative tools or state when not to use it, so it falls short of a 5.

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