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

With no annotations, the description carries the full disclosure burden. It tells the agent what data is returned and that the coin list is optional, but it doesn't cover output format, data source, freshness, rate limits, or edge cases. For a read-only market snapshot this is acceptable though not detailed.

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?

One compact sentence with 'Crypto market overview' leading and no redundant text. Every clause contributes scope or input behavior.

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?

Low-complexity tool with one optional parameter and no output schema. The description explains both the returned data components and the optionality of the only parameter. Missing exact response shape and coin-list format are minor gaps given the simple scope.

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 schema's 100% coverage only says 'Coins to process', while the description adds the crucial meaning that coins are an optional custom list and that omitting them uses top coins. This materially helps invocation, though it doesn't specify the expected string encoding of the list.

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 distinct output: crypto market overview with prices, 24h change for top coins (optional custom list), plus the fear-and-greed index. This differentiates it from narrower sibling tools like x402-crypto-price or x402-fear-greed, though it doesn't explicitly name them.

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?

Implies use when a broad crypto market snapshot is needed, with top coins by default and an optional custom list. It offers no explicit when-not-to-use guidance or named alternatives, so selection relies on the agent infering context.

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