market_today

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

With no annotations, the description carries the full behavioral burden. It does disclose useful semantics — a static snapshot tied to the 'newest published day' rather than a live query — and enumerates the returned dimensions. It omits return shape, units, timestamp/freshness guarantees, and any error or caching 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?

A single front-loaded sentence that begins with the resource and scope before enumerating metrics; no filler sentences. The trailing enumeration is slightly run-on, which keeps it from a 5, but every element is informative.

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 and no annotations, the description must justify trust on its own, and the metric list partially stands in for a return schema. Still missing are the meaning of the metrics, any freshness/timestamp guarantee, and output structure, which for a schema-less read tool is a real 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 takes zero parameters, so the baseline is 4 under the scoring rules; there is nothing for the description to clarify. It appropriately does not invent parameter talk that would not apply.

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?

States a concrete resource and scope: a snapshot of the x402 market on Base for the newest published day, enumerating the metrics returned. It does not, however, distinguish itself from siblings like agents_at_work, which the description effectively also advertises as part of the payload, leaving overlap unresolved.

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?

There is no when-to-use or when-not-to-use guidance and no mention of alternatives such as compare, search, or operator. The agent can infer it fetches a current market summary, but nothing routes it between this and the sibling tools.

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