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

With no annotations, the description carries the full burden and does real work: it discloses the dual access model (0.01 USDC via x402 PAYMENT-SIGNATURE header, or API key with no per-call cost) and the return shape (USD TVL plus per-chain breakdown). It does not mention rate limits or error behavior for unknown protocol names, keeping it short of a 5.

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?

Three tight sentences: purpose and return first, usage trigger second, access/payment logistics last as a bracketed aside. Nothing is redundant and the most decision-relevant information is front-loaded.

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 one-parameter read tool with no output schema, the description covers purpose, return contents, routing context, and payment/auth mechanics. The only real gap is what happens with an unrecognized protocol name or how the per-chain breakdown is keyed.

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% and the single parameter already documents itself as a 'Protocol slug or display name, e.g. aave or uniswap.' The description repeats the examples without adding format constraints, so the baseline 3 applies.

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 resource and scope ('Total Value Locked for a single DeFi protocol') with concrete examples (Aave, Uniswap, Curve) and notes the per-chain breakdown. It implicitly separates itself from get_chain_tvl by scoping to a single protocol, but never names that sibling explicitly.

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?

Gives an explicit trigger: 'Use it when the user asks how much capital is locked in a specific protocol.' That is clear positive guidance, but it offers no exclusions (e.g. 'for chain-level TVL use get_chain_tvl'), leaving the agent to infer routing against get_chain_tvl.

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