Market extremes today

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

Annotations already establish read-only/idempotent behavior; the description adds behavioral detail by specifying 'Descriptive market data only,' that it scans daily across every recorded pair, and that outcome stats are only provided 'where enough events exist.' This goes beyond the structured annotations without contradicting them.

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?

Three sentences, with the core functionality front-loaded in the first sentence and supplementary detail in the second. The third sentence is promotional (developer plan URL) and adds no selection/invocation value, but it is brief and does not significantly hurt readability.

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 parameterless data-query tool with no output schema, the description explains what is returned (pairs at record/5% extremes, next-day outcome stats) and how it is computed (relative to each pair's history, across funding/OI/liq). It leaves some details implicit (exact output structure, threshold definitions beyond '5 percent'), but is sufficient for an agent to decide when to call it.

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 per rubric. The schema coverage is 100% and there is nothing for the description to add beyond confirming parameterless operation; the description's scope statement ('Daily scan across every recorded pair') clarifies what the no-parameter call returns.

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?

Description opens with a specific question: 'Which pairs sit at a record or in their own top or bottom 5 percent for funding, open interest or liquidations.' It clearly identifies the target metric (extremes relative to a pair's own history) and is distinct from sibling tools like funding_matrix or liquidations by combining those metrics with next-day outcome stats.

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 gives clear context: a daily scan across all recorded pairs, and notes it is descriptive market data only, which signals a read-only analytical use case. It does not explicitly name alternative tools or state when not to use it, so it stops 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.