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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds valuable behavior beyond annotations: it is a live data snapshot from DeFiLlama, includes specific output fields, and discloses the $0.02 USDC per-call cost. No contradiction exists.

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?

The description is compact and front-loaded with the core resource, then specifics, then cost. Every sentence adds useful information with no filler or repetitive phrasing.

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 simple read-only tool with two optional parameters and no output schema, the description covers the main output contents, source, and pricing. However, it omits parameter semantics and does not clarify defaults or sorting behavior, leaving slight ambiguity for an agent deciding how to invoke it.

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 description coverage is 0%, so the description must compensate for the undocumented limit and sort_by parameters. It does mention '1D and 7D change', which loosely maps to sort_by enum options, but it never explains limit or default behavior. The agent is left to infer parameter meaning from field names and schema constraints.

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 clearly states the resource ('TVL by blockchain'), the source (DeFiLlama), and specific deliverable metrics (rankings, 1D/7D change, protocol counts, Ethereum dominance, Base vs ETH comparison). This differentiates it from dozens of sibling benchmark tools.

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 phrase 'for x402 agent context' implies an intended use case, but the description does not explicitly say when to choose this tool over related siblings like get_crypto_correlation_benchmark, get_defi_yield_benchmark, or get_stablecoin_yield_benchmark. It offers context but no exclusions or alternative routing.

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