x402_trending

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

With no annotations, the description carries the full burden, and it does disclose two behaviors beyond the name: the $0.02 USDC per-call cost on Base with automatic wallet payment, and the data provenance from daily whole-catalogue snapshots. It stops short of covering failure modes such as insufficient wallet balance or how ties and services with zero calls are handled.

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?

It is one tight paragraph that leads with the concept before the cost note, and every clause carries information. The provenance clause is useful, but the cost and payment details would be easier to scan as their own sentence.

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 two-optional-parameter, output-schema-less tool with no annotations, the description covers what the tool ranks, the data source, and the payment model, which is enough to call it correctly. It omits how many services are represented, how the ordering is presented, or how results behave when a service is new, which would be useful for interpreting the response.

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 both parameters are already fully documented with ranges and defaults, making 3 the baseline. The description reinforces the meaning of days ('versus N days ago') and new entrants, but adds no format or edge-case detail beyond the schema.

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 gives a specific resource and operation: ranking x402 services by gain or loss in paid calls over an N-day window, plus new entrants. This is clearly distinct from catalogue-listing siblings such as x402_services or x402_search, and an agent can tell them apart without opening schemas.

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 implies when to use it by describing trending and movers analysis, but it never explicitly says when this tool is preferable to x402_services or x402_pricing, nor does it state what to use instead. An agent must infer the split from sibling names alone.

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