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 a good job: it discloses the paid model with a concrete price and payment chains, that no auth is required, that failed calls are not charged, and the upstream source (DefiLlama). It does not cover rate limits or response format, keeping it out of the top band.

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?

Information is packed into a few telegraphic clauses and front-loaded with the most decision-relevant facts (paid, what data, cost). It is dense and slightly clipped in style, but no sentence is wasted and the endpoint URL is appended cleanly at the end.

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?

There is no output schema and no parameters, so the description must describe the payload — which it does with a concrete metric list. Combined with pricing, auth, and failure-charge details, an agent has nearly everything needed; only rate limits and exact response structure are unstated.

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. The description needs to add no parameter meaning, and it correctly avoids inventing any while still describing the payload shape (metrics and per-chain breakdown).

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 the specific resource (USDGO stablecoin) and enumerates exactly what data is returned: price vs peg, supply, 1d/7d/30d supply change, and per-chain supply. That is far more specific than the sibling names (e.g. buy_stable_usdc) alone. It stops short of explicitly differentiating itself from other buy_stable_* tools, but the coin is unambiguous.

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 useful context for deciding to call it — it is a paid call ($0.005 USDC on Base or Solana), needs no account or API key, and failed calls are free — but it never states when to prefer this over alternatives such as buy_stable_usdc or the broader buy_cp_stablecoins-check. Usage is implied by the data it returns rather than spelled out.

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