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

Beyond the readOnlyHint/openWorldHint annotations, it discloses a concrete economic behavior — $0.002 USDC per successful call via x402 on Base, Solana or Arc, with failed calls not charged. Pricing and payment-rail details are exactly the kind of behavior an agent must know before invoking.

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?

Two tight sentences: the first front-loads what data is returned, the second covers market selection and cost. Dense but every clause carries information an agent needs; nothing is redundant with the schema or annotations.

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?

An output schema exists, yet the description still summarizes the payload shape, and it covers market selection, defaults, and payment. Nothing an agent needs to call this correctly or anticipate cost is missing.

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 baseline is 3. The description adds value beyond the schema by mapping each market to its Comet contract (cUSDCv3/cWETHv3) and restating the default, though it adds no further syntax or constraint detail.

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 specific verb and resource — on-chain Compound v3 (Comet) market stats on Ethereum — and enumerates the exact fields returned (utilization, supply/borrow APY, totals, collateral assets with factors and caps). This is instantly distinguishable from sibling lending/protocol tools like crypto_aave_lending_markets.

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?

Clear scope: only two markets (usdc/cUSDCv3 or weth/cWETHv3) on Ethereum, with the default stated. It gives strong context for when the tool is applicable, but does not explicitly name an alternative tool or state exclusions for when not to use it.

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