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

With no annotations, the description carries the full behavioral burden and does well: it discloses that the call is paid, the exact price ($0.005 USDC), the accepted payment chains (Base or Solana), that no account or API key is required, and that failed calls are not charged. It omits data freshness/update cadence and rate limits, which are the remaining gaps for a paid data endpoint.

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 front-loaded with the paid status and the data contents, then pricing, then access terms, then the endpoint URL. Every sentence carries information, though the raw URL is arguably redundant with the tool's own routing and the phrase 'stablecoin live' is slightly awkward.

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 zero parameters and no output schema, the description compensates by enumerating the returned data fields and stating the billing/auth model. An agent has everything it needs to decide whether to call it and what the cost and prerequisites are.

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 there is nothing for the description to disambiguate; baseline is 4. The description implicitly confirms the parameterless contract by fixing the subject to avUSD rather than accepting a symbol argument.

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 names a specific resource (Avant USD / avUSD) and enumerates exactly what it returns: price vs peg, supply, 1d/7d/30d supply change, and supply per chain. That makes it distinguishable from the many sibling stablecoin tools. It stops short of explicitly contrasting itself with nearby siblings such as buy_yields_protocol_avant-avusd, which covers yield for the same protocol rather than peg/supply data.

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?

Usage context is implied by the content list (use this when you need avUSD peg and supply metrics), and the payment mechanics are spelled out. However, there is no explicit when-to-use/when-not-to-use guidance and no named alternative for cases like the avUSD yield pool or the broader stablecoin category tools.

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